TOHOKU UNIVERSITY Researchers - Masataka Nakazawa

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Masataka Nakazawa

Section

International Research Institute of Disaster Science

Job title

Specially Appointed Research Fellow

Degree

Doctor of Engineering (Tokyo Institute of Technology)

researchmap

https://researchmap.jp/read0075840

J-GLOBAL ID

200901070716058464

Committee Memberships 2

電子情報通信学会　超高速光エレクトロニクス研究会委員長OFT委員会(1998-2001)、エレクトロニクスソサイエティ会長(2005)

1978/04 - Present
電子情報通信学会　超高速光エレクトロニクス研究会委員長OFT委員会(1998-2001)、エレクトロニクスソサイエティ会長(2005)

1978/04 - Present

Professional Memberships 6

日本光学会(OSJ)
レーザー学会
応用物理学会
電子情報通信学会
OSA
IEEE

︎Show all ︎Show first 5

Research Areas 2

Nanotechnology/Materials / Optical engineering and photonics / Nonlinear optics
Manufacturing technology (mechanical, electrical/electronic, chemical engineering) / Communication and network engineering / Ultrahigh-speed optical communication

Awards 56

第36回電気通信普及財団賞（テレコムシステム技術賞）

2021/03
山梨県中央市市民栄誉賞

2021/02
ICETC 2020 Best Paper Award

2020/12
電子情報通信学会 ELEX Best Paper Award

2020/09
第70回「電波の日」総務大臣表彰

2020/06
Opto-Electronics and Communication Conference (OECC) 2018 Best Paper Award

2018/07
藤原科学財団第56回藤原賞

2015/06
第64回河北文化賞

2015/01
International Wire & Cable Symposium, Inc・Jack Spergel Memorial Award

2014/11
OSA Charles Hard Townes Award

2014/06
NEC C&C財団 2013年度C&C賞

2013/11
微小光学国際会議 MOC Award

2013/10
東北大学総長特別賞

2013/03
第103回(平成25年)日本学士院賞

2013/03
第13回応用物理学会業績賞

2013/03
電子情報通信学会通信ソサイエティ功労顕彰状

2012/09
平成23年度電子情報通信学会論文賞

2012/05
財団法人光産業技術振興協会創立30周年記念功労者表彰

2010/12
第4回(2010年度)応用物理学会フェロー表彰

2010/09
IEEE Photonics Society Quantum Electronics Award

2010/05
平成22年春の勲章紫綬褒章

2010/04
応用物理学会第11回光・量子エレクトロニクス業績賞(宅間宏賞)

2010/03
東北大学総長特別賞

2009/09
電子情報通信学会 2008年ELEX Best Paper Award

2009/09
第8回内閣府産学連携功労者表彰内閣総理大臣賞

2009/06
電子情報通信学会功労賞

2009/05
総務省志田林三郎賞

2008/06
Thomson Scientific Laureate

2006/09　Thomson Scientific
東レ科学技術賞

2006/03　東レ
R. W. Wood Prize

2005/05　Optical Society of America　For invention of the 1.48μm InGaAsP laser-diode-pumped erbium-doped fiber
第35回新技術開発財団市村産業賞

2003/04　新技術開発財団
IEEE Daniel E. Noble Award

2002/12　IEEE
第72回服部報公会報公賞

2002/10　服部報公会
第27回科学技術振興事業団井上春成賞

2002/07　科学技術振興事業団
電子情報通信学会猪瀬賞

2002/05　電子情報通信学会　位相変調器による3次、４次分散同時補償を用いた1.28Tbit/s-70kmフェムト秒パルスOTDM伝送
電子情報通信学会論文賞

2002/04　電子情報通信学会　位相変調器による3次、４次分散同時補償を用いた1.28Tbit/s-70kmフェムト秒パルスOTDM伝送
電子情報通信学会フォロー

2001/09　電子情報通信学会
電子情報通信学会論文賞

2000/05　電子情報通信学会
NTT R&Dフェロー

1999/04　NTT
電子情報通信学会論文賞

1998/05　電子情報通信学会
第13回電気通信普及財団テレコムシステム技術賞

1998/03　電気通信普及財団
科学技術庁長官賞(研究功績者賞)

1997/04　科学技術庁
電子情報通信学会業績賞

1996/05　電子情報通信学会
IEEE Fellow Award

1995/01　IEEE
Fifth OptoElectronics Conference(OEC'94)Best Paper Award

1994/07　.
電子情報通信学会業績賞

1994/05　電子情報通信学会
電子情報通信学会論文賞

1994/05　電子情報通信学会
レーザー学会研究業績賞

1993/05　レーザー学会
科学技術庁長官注目発明表彰

1993/04　科学技術庁
OSA(Optical Society of America)Fellow Award

1992/06　OSA
応用物理学会会誌賞

1991/10　応用物理学会
IEE, Electronics Letters Premium Award, United Kingdom

1990/10　IEE
第5回桜井健二郎記念賞

1989/11　.
応用物理学会光学論文賞

1985/03　応用物理学会
電子通信学会学術奨励賞

1983/04　電子通信学会
丹羽保次郎記念賞

1980/03　.

Show all ︎Show 5

Papers 1012

108 Gbit/s, 64 QAM fully-coherent mobile-fronthaul transmission over 10 km SMF and 70 m wirelessly in the 125 GHz band Peer-reviewed

Tomoki Joichi, Arata Watanabe, Keisuke Kasai, Toshihiko Hirooka, Masato Yoshida, Masataka Nakazawa

Optics Express　34　(4)　6345-6345　2026/02/12
Publisher: Optica Publishing Group
DOI： 10.1364/oe.579647 　

eISSN： 1094-4087

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We report a 108 Gbit/s fully coherent optical-wireless transmission in the 125 GHz band for 6G mobile fronthaul. Using an injection-locked heterodyne detection scheme, we generated a 125 GHz-IF signal with a single-sideband phase noise of 3.2 degrees, which was sufficiently low for the demodulation of a 64 QAM data signal. By applying a digital pre-equalization scheme, we successfully transmitted an 18 Gbaud 64 QAM signal over a 10 km single-mode fiber and over 70 m wirelessly with a spectral efficiency of 5.71 bit/s/Hz.
I-, Q-, and I/Q-simultaneously bifurcated photonic Ising machines with Kerr nonlinearity

Masataka Nakazawa, Toshihiko Hirooka

OPTICS EXPRESS　33　(24)　51513-51533　2025/12/01

DOI： 10.1364/OE.578292 　

ISSN： 1094-4087
Novel Polarization-Dependence-Free Optical Injection-Locking Circuit Using $\lambda / 4$ Phase-Shift-Free HR DFB LD at $1.5 \mu ~\mathrm{m}$

Keisuke Kasai, Shun Otsu, Masato Yoshida, Toshihiko Hirooka, Masataka Nakazawa

2025 European Conference on Optical Communications (ECOC)　1-4　2025/09/28
Publisher: IEEE
DOI： 10.1109/ecoc66593.2025.11263060 　
Kerr-resonanced bifurcation switching in a photonic Ising machine with a long lossless optical fiber loop Peer-reviewed

Masataka Nakazawa, Toshihiko Hirooka

Optics Express　33　(18)　37559-37559　2025/08/26
Publisher: Optica Publishing Group
DOI： 10.1364/oe.568935 　

eISSN： 1094-4087

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We describe in detail the optical Kerr nonlinearity in our photonic Ising machine (PIM), which employs ultrahigh-speed optical pulse propagation in a lossless fiber loop. Although the peak power of the pulses in the fiber loop is set as low as ∼1 mW, the present PIM requires ultralong-distance pulse propagation of the order of 100,000 km (e.g., ∼2,000 circulations in a 50 km loop) to calculate large-scale optimization problems. As a result, a nonlinear phase rotation of greater than π/2 is accumulated due to the Kerr effect. This nonlinear phase rotation makes it possible to couple between the real ( I ) and imaginary ( Q ) parts of the recirculating optical pulse. Thus, as the amplitude of the I -channel changes due to the nonlinear phase rotation, the Q -channel also varies accordingly, and vice versa. We show that this mutual coupling gives rise to a new phenomenon, which we name Kerr-resonanced bifurcation switching, where the accumulated nonlinear phase rotation results in a periodic dip in the cut value of a max-cut problem. This dip phenomenon can be understood as a consequence of optical power peaking in a nonlinear optical fiber loop resonator with Kerr phase rotation. Finally, we propose a method for preventing dip generation by combining a large core fiber and a chirped fiber Bragg grating (CFBG) over a short length, which can reduce the Kerr-induced nonlinear phase rotation.
Guided acoustic-wave Brillouin scattering noise in few-mode fiber Peer-reviewed

Masato Yoshida, Tetsuya Yoshida, Shohei Beppu, Yuta Wakayama, Noboru Yoshikane, Keisuke Kasai, Toshihiko Hirooka, Masataka Nakazawa

Optics Express　33　(16)　34586-34586　2025/08/05
Publisher: Optica Publishing Group
DOI： 10.1364/oe.570713 　

eISSN： 1094-4087

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We describe theoretical and experimental analyses of guided acoustic wave Brillouin scattering (GAWBS) noise in few-mode fiber (FMF). First, we theoretically show the mechanism of GAWBS noise generation through mode-coupling between different linearly polarized (LP) modes in FMF. We show that acoustic modes with wavenumbers along the fiber propagating axis contribute to the mode-coupling in the FMF. Next, we calculate the power spectra of GAWBS noise generated between identical LP modes, different LP modes, and degenerate LP modes in an FMF supporting six LP modes. We then measure the GAWBS noise spectra using a self-delayed heterodyne detection method and confirm good agreement with the calculated results. We find that GAWBS noise generated through mode-coupling between different LP modes exhibits reversibility with respect to the direction of the mode-coupling. Furthermore, we show that GAWBS phase noise generated between different LP modes is converted into intensity noise due to the different group velocities among LP modes in the FMF. We also clarify that the GAWBS noise coefficient is 3 to 4 dB higher than that in standard single-mode fiber (SSMF) since it experiences simultaneous mode-coupling from all LP modes. Finally, we evaluate the impact of GAWBS noise on digital coherent transmission with FMF using the Gaussian noise (GN) model and show that it can cause a substantial transmission distance penalty of as high as 27.7 ∼ 30.0%.
Coherently-Linked Optical and Wireless Transmission for 6G Mobile Fronthaul

Keisuke Kasai, Arata Watanabe, Masato Yoshida, Toshihiko Hirooka, Masataka Nakazawa

2025 30th OptoElectronics and Communications Conference (OECC) and 2025 International Conference on Photonics in Switching and Computing (PSC)　1-3　2025/06/29
Publisher: IEEE
DOI： 10.23919/oecc/psc62146.2025.11110340 　
Single-Channel 108 Gbit/s, 64 QAM Fully Coherent Mobile Fronthaul Transmission at 125 GHz-IF

Tomoki Joichi, Keisuke Kasai, Toshihiko Hirooka, Masato Yoshida, Masataka Nakazawa

2025 30th OptoElectronics and Communications Conference (OECC) and 2025 International Conference on Photonics in Switching and Computing (PSC)　1-3　2025/06/29
Publisher: IEEE
DOI： 10.23919/oecc/psc62146.2025.11110001 　
An Oscillator-Less Photonic Ising Machine With Digital-Nonlinearity-Based Bifurcation and Its Simulated Application to a 1 Million-Node Fully Connected Max-Cut Problem Peer-reviewed

Masataka Nakazawa, Toshihiko Hirooka

Journal of Lightwave Technology　43　(12)　5579-5600　2025/06/15
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
DOI： 10.1109/jlt.2025.3552250 　

ISSN： 0733-8724

eISSN： 1558-2213
Coherent all Optical Reservoir Computing for Equalization of Impairments in Coherent Fiber Optic Communication Systems

Shiva Kumar, Mahmoud M. T. Maghrabi, Mohamed H. Bakr, Toshihiko Hirooka, Masataka Nakazawa

IEEE PHOTONICS JOURNAL　16　(5)　2024/10

DOI： 10.1109/JPHOT.2024.3462438 　

ISSN： 1943-0655

eISSN： 1943-0647
Coherent Nyquist optical pulse transmission at nearly 1-Tb/s/λ over 1,600 km with a capacity of 21.5 Tb/s using PS-32 QAM signals

Shohei Beppu, Aoto Ishikawa, Takeki Serikawa, Masato Yoshida, Toshihiko Hirooka, Masataka Nakazawa

Optics Express　32　(9)　16533-16533　2024/04/19
Publisher: Optica Publishing Group
DOI： 10.1364/oe.518396 　

eISSN： 1094-4087

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We demonstrate the 1,600-km transmission at nearly 1-Tb/s/λ signals with a capacity of 21.5 Tb/s. Probabilistic shaping was newly applied to high-speed coherent optical Nyquist pulse transmission systems to maximize the transmission capacity. Employing a 160-GBd PS-32 QAM format, WDM signals at nearly 1-Tb/s/λ were successfully transmitted over 1,600 km with a capacity of 21.5 Tb/s.
Eigen-function division multiplexed coherent optical transmission in time domain by using higher-order Hermite-Gaussian pulses

Masataka Nakazawa, Masato Yoshida, Toshihiko Hirooka

Optics Express　32　(7)　12682-12682　2024/03/21
Publisher: Optica Publishing Group
DOI： 10.1364/oe.510189 　

eISSN： 1094-4087

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We describe a new multiplexing technique and its application to demultiplexing in the time domain by using higher-order Hermite-Gaussian (HG) pulses, which are solutions of the Schrödinger equation. We call this technique eigen-function division multiplexing (EDM). This method enables us to further increase the total transmission capacity by superimposing many different HG pulses in the same time slot. This technique is different from a conventional optical time domain multiplexing (OTDM) technique using interleaving, where one pulse exists only in one time slot. The transmitted EDM HG pulses can be demultiplexed by adopting the time-domain orthogonality of the HG pulses (eigen-function orthogonality). The information carried by the mth-order HG pulse (HG_m pulse) can be coherently detected by a photo detector, where photo-mixing with a phase-locked HG_m pulse generated by a local oscillator can realize demultiplexing. The overlap integral with a different HG pulse becomes zero due to the time domain orthogonality. First, we show numerically that such a new EDM transmission scheme in the time domain is possible. We then show experimentally that we could successfully carry out an EDM HG coherent pulse transmission with four different HG pulses (HG₀, HG₁, HG₂, and HG₃), where we report a 400∼480 Gbit/s (10 Gbaud x 4 eigen-functions x 2 pol-mux.) 32∼64 QAM EDM transmission over 300∼450 km.
Experiments on the Generation of Higher-Order Hermite-Gaussian Pulses From an FM Mode-Locked Laser

Masataka Nakazawa, Masato Yoshida, Toshihiko Hirooka

IEEE Journal of Quantum Electronics　59　(6)　1-16　2023/12
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
DOI： 10.1109/jqe.2023.3305121 　

ISSN： 0018-9197

eISSN： 1558-1713
Demodulation Performance Comparison of High-Speed Coherent Nyquist Pulse Signal with Analog and Digital Demultiplexing Schemes

Masato YOSHIDA, Kosuke KIMURA, Toshihiko HIROOKA, Keisuke KASAI, Masataka NAKAZAWA

IEICE Transactions on Communications　E106.B　(11)　1059-1064　2023/11/01
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
DOI： 10.1587/transcom.2022obp0001 　

ISSN： 0916-8516

eISSN： 1745-1345
GAWBS Noise in Digital Coherent Transmission

Masataka Nakazawa, Masato Yoshida, Toshihiko Hirooka

Journal of Lightwave Technology　41　(11)　3358-3371　2023/06/01
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
DOI： 10.1109/jlt.2023.3255942 　

ISSN： 0733-8724

eISSN： 1558-2213
Experiments on Generation of Various Dark and Bright Pulses From an FM Mode-Locked Laser

Masataka Nakazawa, Masato Yoshida, Toshihiko Hirooka

IEEE Journal of Quantum Electronics　58　(6)　1-23　2022/12
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
DOI： 10.1109/jqe.2022.3210339 　

ISSN： 0018-9197

eISSN： 1558-1713
Experimental and Numerical Analysis of Ultrahigh-Speed Coherent Nyquist Pulse Transmission with Low-Nonlinearity Dispersion Compensator

Kosuke KIMURA, Masato YOSHIDA, Keisuke KASAI, Toshihiko HIROOKA, Masataka NAKAZAWA

IEICE Transactions on Communications　E105.B　(9)　1014-1022　2022/09/01
Publisher: Institute of Electronics, Information and Communications Engineers (IEICE)
DOI： 10.1587/transcom.2021ebp3178 　

ISSN： 0916-8516

eISSN： 1745-1345
Characterization of Inter-core Crosstalk of Multi-core Fiber as a Function of Bending Radius with Multi-channel OTDR

Yuto Kobayashi, Takahiro Suganuma, Tetsuya Hayashi, Takemi Hasegawa, Masato Yoshida, Masataka Nakazawa

2022 27th OptoElectronics and Communications Conference (OECC) and 2022 International Conference on Photonics in Switching and Computing (PSC)　2022/07/03
Publisher: IEEE
DOI： 10.23919/oecc/psc53152.2022.9850127 　
Demodulation Performance Comparison of 160 Gbaud Coherent Nyquist Pulse Signal with Analog and Digital DEMUX Schemes

Masato Yoshida, Kosuke Kimura, Keisuke Kasai, Toshihiko Hirooka, Masataka Nakazawa

2022 27th OptoElectronics and Communications Conference (OECC) and 2022 International Conference on Photonics in Switching and Computing (PSC)　2022/07/03
Publisher: IEEE
DOI： 10.23919/oecc/psc53152.2022.9849876 　
10.2 Tbit/s (1.28 Tbit/s/ch x 8 ch) WDM Nyquist Pulse Transmission over 2100 km

Aoi Watanabe, Aoto Ishikawa, Masato Yoshida, Toshihiko Hirooka, Masataka Nakazawa

2022 27th OptoElectronics and Communications Conference (OECC) and 2022 International Conference on Photonics in Switching and Computing (PSC)　2022/07/03
Publisher: IEEE
DOI： 10.23919/oecc/psc53152.2022.9849931 　
GAWBS noise in multicore fibers

Masato Yoshida, Masataka Nakazawa

2022 27th OptoElectronics and Communications Conference (OECC) and 2022 International Conference on Photonics in Switching and Computing (PSC)　2022/07/03
Publisher: IEEE
DOI： 10.23919/oecc/psc53152.2022.9849900 　
Software-Defined Fiber Optic Communications for Ultrahigh-Speed Optical Pulse Transmission Systems

Mahdi Naghshvarianjahromi, Shiva Kumar, M. Jamal Deen, Taro Iwaya, Kosuke Kimura, Masato Yoshida, Toshihiko Hirooka, Masataka Nakazawa

IEEE JOURNAL OF SELECTED TOPICS IN QUANTUM ELECTRONICS　28　(4)　2022/07

DOI： 10.1109/JSTQE.2022.3190885 　

ISSN： 1077-260X

eISSN： 1558-4542
Software-Defined Fiber Optic Communications for Ultrahigh-Speed Optical Pulse Transmission Systems

Mahdi Naghshvarianjahromi, Shiva Kumar, M. Jamal Deen, Taro Iwaya, Kosuke Kimura, Masato Yoshida, Toshihiko Hirooka, Masataka Nakazawa

IEEE Journal of Selected Topics in Quantum Electronics　28　(4)　1-10　2022/07
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
DOI： 10.1109/jstqe.2022.3190885 　

ISSN： 1077-260X

eISSN： 1558-4542
Experiments on an AM Mode-Locked Laser as an Arbitrary Optical Function Generator

Masataka Nakazawa, Masato Yoshida, Toshihiko Hirooka

IEEE JOURNAL OF QUANTUM ELECTRONICS　58　(3)　2022/06

DOI： 10.1109/JQE.2022.3165322 　

ISSN： 0018-9197

eISSN： 1558-1713
Experiments on an FM Mode-Locked Laser as an Arbitrary Optical Function Generator

Masataka Nakazawa, Masato Yoshida, Toshihiko Hirooka

IEEE JOURNAL OF QUANTUM ELECTRONICS　58　(3)　2022/06

DOI： 10.1109/JQE.2022.3165317 　

ISSN： 0018-9197

eISSN： 1558-1713
Broadband injection-locked homodyne receiver for digital coherent transmission using a low Q Fabry-Perot LD

Keisuke Kasai, Takashi Kan, Masato Yoshida, Toshihiko Hirooka, Masataka Nakazawa

OPTICS EXPRESS　30　(8)　13345-13355　2022/04

DOI： 10.1364/OE.456327 　

ISSN： 1094-4087
Precise Measurements and their Analysis of GAWBS-Induced Depolarization Noise in Multi-Core Fiber for Digital Coherent Transmission

Masato Yoshida, Kozo Sato, Toshihiko Hirooka, Keisuke Kasai, Masataka Nakazawa

IEICE TRANSACTIONS ON COMMUNICATIONS　E105B　(2)　151-158　2022/02

DOI： 10.1587/transcom.2021CEP0006 　

ISSN： 0916-8516

eISSN： 1745-1345
Measurement of Mode-Coupling Along a Multi-Core Submarine Fiber Cable with a Multi-Channel OTDR

Masato Yoshida, Toshihiko Hirooka, Nakazawa Masataka, Tetsuya Hayashi, Takemi Hasegawa, Kohei Nakamura, Takanori Inoue

2022 EUROPEAN CONFERENCE ON OPTICAL COMMUNICATION (ECOC)　2022
Measurement of Mode-Coupling Along a Multi-Core Submarine Fiber Cable with a Multi-Channel OTDR

Masato Yoshida, Toshihiko Hirooka, Nakazawa Masataka, Tetsuya Hayashi, Takemi Hasegawa, Kohei Nakamura, Takanori Inoue

2022 European Conference on Optical Communication, ECOC 2022　2022
Distributed Measurement of Rayleigh Backscattered Crosstalk for Bidirectional Multicore Fiber Transmissions Using Multi-Channel Optical Time Domain Reflectometry

Yuto Kobayashi, Tetsuya Hayashi, Takemi Hasegawa, Takahiro Suganuma, Inoue Ayumi, Takuji Nagashima, Hirotaka Sakuma, Takahiro Kikuchi, Osamu Shimakawa, Hidehisa Tazawa, Masato Yoshida, Masataka Nakazawa

2022 European Conference on Optical Communication, ECOC 2022　2022
Optical Fibers for Space-Division Multiplexing

Masaharu Ohashi, Shoichiro Matsuo, Tetsuya Hayashi, Katsunori Imamura, Yasuo Kokubun, Masanori Koshiba, Takayoshi Mori, Kazuhide Nakajima, Masataka Nakazawa, Kunimasa Saitoh, Taiji Sakamoto, Takashi Sasaki

Springer Series in Optical Sciences　236　39-170　2022

DOI： 10.1007/978-3-030-87619-7_2 　

ISSN： 0342-4111

eISSN： 1556-1534
Theory of AM Mode-Locking of a Laser as an Arbitrary Optical Function Generator

Masataka Nakazawa, Toshihiko Hirooka

IEEE Journal of Quantum Electronics　57　(6)　2021/12/01
Publisher: Institute of Electrical and Electronics Engineers Inc.
DOI： 10.1109/JQE.2021.3114173 　

ISSN： 1558-1713 0018-9197
GAWBS noise correlation between cores in multi-core fibers

Kozo Sato, Masato Yoshida, Keisuke Kasai, Toshihiko Hirooka, Masataka Nakazawa

OPTICS EXPRESS　29　(26)　42523-42537　2021/12

DOI： 10.1364/OE.442261 　

ISSN： 1094-4087
A generalized mode-locking theory for a Nyquist laser with an arbitrary roll-off factor Part I: Master equations and optical filters in a Nyquist laser

Masataka Nakazawa, Toshihiko Hirooka

IEEE Journal of Quantum Electronics　57　(3)　2021/06/01
Publisher: Institute of Electrical and Electronics Engineers Inc.
DOI： 10.1109/JQE.2021.3065960 　

ISSN： 1558-1713 0018-9197
A Generalized Mode-Locking Theory for a Nyquist Laser with an Arbitrary Roll-Off Factor PART II: Oscillation Waveforms and Spectral Characteristics

Masataka Nakazawa, Toshihiko Hirooka

IEEE Journal of Quantum Electronics　57　(3)　2021/06/01
Publisher: Institute of Electrical and Electronics Engineers Inc.
DOI： 10.1109/JQE.2021.3065935 　

ISSN： 1558-1713 0018-9197
10 Channel WDM 80 Gbit/s/ch, 256 QAM Bi-Directional Coherent Transmission for a High Capacity Next-Generation Mobile Fronthaul

Masato Yoshida, Takashi Kan, Keisuke Kasai, Toshihiko Hirooka, Katsumi Iwatsuki, Masataka Nakazawa

JOURNAL OF LIGHTWAVE TECHNOLOGY　39　(5)　1289-1295　2021/03/01

DOI： 10.1109/JLT.2020.3034417 　

ISSN： 0733-8724

eISSN： 1558-2213
10 Channel WDM 80 Gbit/s/ch, 256 QAM Bi-Directional Coherent Transmission for a High Capacity Next-Generation Mobile Fronthaul

Masato Yoshida, Takashi Kan, Keisuke Kasai, Toshihiko Hirooka, Katsumi Iwatsuki, Masataka Nakazawa

JOURNAL OF LIGHTWAVE TECHNOLOGY　39　(5)　1289-1295　2021/03

DOI： 10.1109/JLT.2020.3034417 　

ISSN： 0733-8724

eISSN： 1558-2213
Ultrahigh-Speed Nyquist Pulse Transmission Beyond 10 Tbit/s

Masato Yoshida, Toshihiko Hirooka, Masataka Nakazawa

IEEE JOURNAL OF SELECTED TOPICS IN QUANTUM ELECTRONICS　27　(2)　2021/03

DOI： 10.1109/JSTQE.2020.3011939 　

ISSN： 1077-260X

eISSN： 1558-4542
Chromatic dispersion dependence of GAWBS phase noise compensation with pilot tone

Kozo Sato, Takashi Kan, Masato Yoshida, Keisuke Kasai, Toshihiko Hirooka, Masataka Nakazawa

OPTICS EXPRESS　29　(7)　10676-10687　2021/03

DOI： 10.1364/OE.418891 　

ISSN： 1094-4087
10 Tbit/s QAM Quantum Noise Stream Cipher Coherent Transmission Over 160 Km

Masato Yoshida, Takashi Kan, Keisuke Kasai, Toshihiko Hirooka, Masataka Nakazawa

JOURNAL OF LIGHTWAVE TECHNOLOGY　39　(4)　1056-1063　2021/02/15

DOI： 10.1109/JLT.2020.3016693 　

ISSN： 0733-8724

eISSN： 1558-2213
10 Tbit/s QAM Quantum Noise Stream Cipher Coherent Transmission over 160 Km

Masato Yoshida, Takashi Kan, Keisuke Kasai, Toshihiko Hirooka, Masataka Nakazawa

Journal of Lightwave Technology　39　(4)　1056-1063　2021/02/15
Publisher: Institute of Electrical and Electronics Engineers Inc.
DOI： 10.1109/JLT.2020.3016693 　

ISSN： 1558-2213 0733-8724
Experimental demonstration of distortion mitigation in 15 Tbit/s OTDM transmission using a cognitive dynamic system

Mahdi Naghshvarianjahromi, Shiva Kumar, Jamal Deen, Taro Iwaya, Kosuke Kimura, Masato Yoshida, Toshihiko Hirooka, Masataka Nakazawa

26th Optoelectronics and Communications Conference　2021
Publisher: OSA
DOI： 10.1364/oecc.2021.t4b.8 　
Single-Channel 1.28 Tbit/s Optical Nyquist Pulse Transmission over 3000 km with Roll-off Factor Optimization

Aoi Watanabe, Masato Yoshida, Toshihiko Hirooka, Masataka Nakazawa

26th Optoelectronics and Communications Conference　2021
Publisher: OSA
DOI： 10.1364/oecc.2021.t4b.6 　
Broadband Dynamic Injection-Locking Performance of Fabry-Perot LD and Its Application to Coherent Homodyne Receiver

Takashi Kan, Keisuke Kasai, Masato Yoshida, Toshihiko Hirooka, Masataka Nakazawa

2021 OPTICAL FIBER COMMUNICATIONS CONFERENCE AND EXPOSITION (OFC)　2021
64 Gbit/s, 256 QAM Transmission Through Coherent Optical-Wireless Link at 61 GHz Using Simple and High OSNR Carrier Frequency Converter

Keisuke Kasai, Taisei Sato, Toshihiko Hirooka, Masato Yoshida, Masataka Nakazawa

2021 OPTICAL FIBER COMMUNICATIONS CONFERENCE AND EXPOSITION (OFC)　2021
GAWBS Noise Correlation Between Cores in Four-Core Fiber

Kozo Sato, Masato Yoshida, Keisuke Kasai, Toshihiko Hirooka, Masataka Nakazawa

2021 OPTICAL FIBER COMMUNICATIONS CONFERENCE AND EXPOSITION (OFC)　2021
Spectrally efficient pilot tone-based compensation of inter-channel cross-phase modulation noise in a WDM coherent transmission using injection locking

Takashi Kan, Kozo Sato, Masato Yoshida, Toshihiko Hirooka, Keisuke Kasai, Masataka Nakazawa

OPTICS EXPRESS　29　(2)　1454-1469　2021/01

DOI： 10.1364/OE.414381 　

ISSN： 1094-4087
Study on chromatic dispersion dependence of GAWBS noise

佐藤耕造, 管貴志, 吉田真人, 葛西恵介, 廣岡俊彦, 中沢正隆

電子情報通信学会技術研究報告(Web)　120　(309(OCS2020 27-39))　2021

ISSN： 2432-6380
12.8 Tbit/s (1.28 Tbit/s/ch x 10) OTDM-WDM Transmission of PDM-DQPSK Optical Nyquist Pulses over 1500 km

渡邊碧, 吉田真人, 廣岡俊彦, 中沢正隆

電子情報通信学会技術研究報告(Web)　120　(309(OCS2020 27-39))　2021

ISSN： 2432-6380
Toward optical and wireless convergence with coherently-linked access network

廣岡俊彦, 葛西恵介, 吉田真人, 中沢正隆

電子情報通信学会技術研究報告(Web)　120　(341(SR2020 47-59))　2021

ISSN： 2432-6380
Study on Chromatic Dispersion Dependence of GAWBS Noise

佐藤耕造, 管貴志, 吉田真人, 葛西恵介, 廣岡俊彦, 中沢正隆

電子情報通信学会大会講演論文集(CD-ROM)　2021　2021

ISSN： 1349-144X
12.8 Tbit/s (1.28 Tbit/s/ch x 10) OTDM-WDM Transmission of PDM-DQPSK Optical Nyquist Pulses over 1500 km

渡邊碧, 吉田真人, 廣岡俊彦, 中沢正隆

電子情報通信学会大会講演論文集(CD-ROM)　2021　2021

ISSN： 1349-144X
Coherently-linked optical and wireless access system for next generation RAN

中沢正隆

電子情報通信学会大会講演論文集(CD-ROM)　2021　2021

ISSN： 1349-144X
BER performance improvement of ultrahigh-speed coherent Nyquist pulse transmission using low-nonlinearity, dispersion-compensated transmission line with chirped FBG and LCoS

木村光佑, 木村光佑, 吉田真人, 葛西恵介, 廣岡俊彦, 中沢正隆

電子情報通信学会技術研究報告(Web)　121　(18(OFT2021 1-11))　2021

ISSN： 2432-6380
Precise and Wideband Compensation of WDM Inter-Channel Cross-Phase Modulation Noise Using Injection Locking

管貴志, 佐藤耕造, 吉田真人, 葛西恵介, 廣岡俊彦, 中沢正隆

電子情報通信学会大会講演論文集(CD-ROM)　2021　2021

ISSN： 1349-144X
Low-Nonlinearity, Dispersion-Compensated Transmission Line with a Chirped Fiber Bragg Grating and LCoS and Its Application to Ultrahigh-Speed Coherent Nyquist Pulse Transmission

岩屋太郎, 木村光佑, 吉田真人, 葛西恵介, 廣岡俊彦, 中沢正隆

電子情報通信学会大会講演論文集(CD-ROM)　2021　2021

ISSN： 1349-144X
Injection-locked 256 QAM WDM coherent transmissions in the C- and L-bands

Takashi Kan, Keisuke Kasai, Masato Yoshida, Toshihiko Hirooka, Masataka Nakazawa

OPTICS EXPRESS　28　(23)　34665-34676　2020/11

DOI： 10.1364/OE.404786 　

ISSN： 1094-4087
Precise measurements and their analysis of GAWBS-induced depolarization noise in various optical fibers for digital coherent transmission

Masato Yoshida, Naoya Takefushi, Keisuke Kasai, Toshihiko Hirooka, Masataka Nakazawa

OPTICS EXPRESS　28　(23)　34422-34433　2020/11

DOI： 10.1364/OE.409326 　

ISSN： 1094-4087
Digital Coherent Optical Access Technologies for beyond 5G Network

Keisuke Kasai, Masataka Nakazawa, Masato Yoshida, Katsumi Iwatsuki, Toshihiko Hirooka

2020 IEEE International Symposium on Radio-Frequency Integration Technology, RFIT 2020　145-147　2020/09/01
Publisher: Institute of Electrical and Electronics Engineers Inc.
DOI： 10.1109/RFIT49453.2020.9226206 　
GAWBS phase noise characteristics in multi-core fibers for digital coherent transmission

Naoya Takefushi, Masato Yoshida, Keisuke Kasai, Toshihiko Hirooka, Masataka Nakazawa

OPTICS EXPRESS　28　(15)　23012-23022　2020/07

DOI： 10.1364/OE.399202 　

ISSN： 1094-4087
Evaluation of Systematic Errors in the Compact Absolute Gravimeter TAG-1 for Network Monitoring of Volcanic Activities

Akito Araya, Keisuke Kasai, Masato Yoshida, Masataka Nakazawa, Tsuneya Tsubokawa

International Association of Geodesy Symposia　2020/04/29
Publisher: Springer Berlin Heidelberg
DOI： 10.1007/1345_2020_107 　

ISSN： 0939-9585

eISSN： 2197-9359

More details Close

Abstract Volcanic activities sometimes involve gravity changes, and this research is intended to establish an observation network surrounding an active volcano using compact absolute gravimeters. To simplify the configuration of absolute gravimeters, they are preferably operated with a light source distributed from a telecom band (wavelength of 1.5 μm) laser through optical fibers. To evaluate the accuracy of the absolute gravimeter with the telecom band laser, we conducted observations using a prototype gravimeter (TAG-1) with frequency-stabilized lasers at both 1.5 μm and 633 nm, and compared these results with the expected gravity at the site. Initially, both results showed offsets −187 μGal and −9.6 μGal for the 1.5-μm laser and the 633-nm laser, respectively (1 Gal = 10⁻⁸ m/s²). By correcting the systematic errors of the photo detectors measured by the synthetic chirp signal, the obtained absolute gravity was consistent with the expected value for both wavelengths; offsets from the expected gravity were reduced to 6.6 μGal and 5.4 μGal for 1.5 μm and 633 nm, respectively. We also evaluated the errors associated with long-distance transmission of the 1.5-μm laser using a reeled optical fiber (26 km) and an optical amplifier and found no degradation in the gravity data from the case of short transmission (10 m). These results allow networking of compact absolute gravimeters connected by telecom optical fibers that are operated using a common laser and expansion to volcanic areas to monitor the gravity change associated with volcanic activities.
Theoretical and experimental analyses of GAWBS phase noise in various optical fibers for digital coherent transmission

Naoya Takefushi, Masato Yoshida, Keisuke Kasai, Toshihiko Hirooka, Masataka Nakazawa

OPTICS EXPRESS　28　(3)　2873-2883　2020/02

DOI： 10.1364/OE.384505 　

ISSN： 1094-4087
Low-Nonlinearity, Dispersion-Compensated Transmission Line with a Chirped Fiber Bragg Grating and Its Application to Ultrahigh-Speed Coherent Nyquist Pulse Transmission

Taro Iwaya, Kosuke Kimura, Masato Yoshida, Keisuke Kasai, Toshihiko Hirooka, Masataka Nakazawa

2020 OPTO-ELECTRONICS AND COMMUNICATIONS CONFERENCE (OECC 2020)　2020

ISSN： 2166-8884

eISSN： 2166-8892
Precise and Wideband Compensation of Inter-Channel Cross-Phase Modulation Noise in WDM Coherent Transmission Using Injection Locking

Takashi Kan, Kozo Sato, Masato Yoshida, Keisuke Kasai, Toshihiko Hirooka, Masataka Nakazawa

2020 OPTO-ELECTRONICS AND COMMUNICATIONS CONFERENCE (OECC 2020)　2020

ISSN： 2166-8884

eISSN： 2166-8892
Chromatic Dispersion Dependence of GAWBS Noise

Kozo Sato, Takashi Kan, Masato Yoshida, Keisuke Kasai, Toshihiko Hirooka, Masataka Nakazawa

2020 OPTO-ELECTRONICS AND COMMUNICATIONS CONFERENCE (OECC 2020)　2020

ISSN： 2166-8884

eISSN： 2166-8892
Research Project to Realize Various High-reliability Communications in Advanced 5G Network.

Takahide Murakami, Yoji Kishi, Koji Ishibashi, Keisuke Kasai, Hiroyuki Shinbo, Morihiko Tamai, Kensuke Tsuda, Masataka Nakazawa, Yu Tsukamoto, Hiroyuki Yokoyama, Yoshimi Fujii, Yuta Seki, Shinobu Nanba, Takanori Hara, Fumiyuki Adachi, Takayuki Sotoyama

2020 IEEE Wireless Communications and Networking Conference(WCNC)　1-8　2020
Publisher: IEEE
DOI： 10.1109/WCNC45663.2020.9120477 　
64 Gbit/s, 256 QAM Coherently-Linked Optical and Wireless Transmission in 61 GHz Band Using Novel Injection-Locked Carrier Frequency Converter.

Keisuke Kasai, Toshihiko Hirooka, Masato Yoshida, Masataka Nakazawa

European Conference on Optical Communications(ECOC)　1-3　2020
Publisher: IEEE
DOI： 10.1109/ECOC48923.2020.9333340 　
Next Generation C-RAN Mobile Fronthaul Using On-line Bi-directional 256 QAM WDM Coherent Transmission

管貴志, 吉田真人, 葛西恵介, 廣岡俊彦, 岩月勝美, 中沢正隆

電子情報通信学会技術研究報告　119　(366(OCS2019 65-77)(Web))　2020

ISSN： 0913-5685
R&D of Technology for High Reliability Management of Advanced 5G Network to Various Requirements of Communication Services

村上隆秀, 新保宏之, 塚本優, 難波忍, 岸洋司, 玉井森彦, 横山浩之, 原郁紀, 石橋功至, 津田顕祐, 藤井義巳, 安達文幸, 葛西惠介, 中沢正隆, 関裕太, 外山隆行

電子情報通信学会技術研究報告　119　(448(RCS2019 320-408)(Web))　2020

ISSN： 0913-5685
10 GHz, 6.2 ps Transform-Limited Coherent Optical Pulse Generation from a 1.55 μm, Self-Injection Gain-Switched DFB-LD.

Keisuke Kasai, Masataka Nakazawa

電子情報通信学会大会講演論文集(CD-ROM)　2020　1-3　2020
Publisher: IEEE
ISSN： 1349-144X
Effect of GAWBS Depolarization Noise on Digital Coherent Optical Transmission

竹節直也, 吉田真人, 葛西恵介, 廣岡俊彦, 中沢正隆

電子情報通信学会大会講演論文集(CD-ROM)　2020　2020

ISSN： 1349-144X
A proposal on optical-wireless mobile fronthaul for advanced 5G

中沢正隆, 葛西恵介, 吉田真人, 廣岡俊彦, 岩月勝美

電子情報通信学会大会講演論文集(CD-ROM)　2020　2020

ISSN： 1349-144X
Single-channel 15.3 Tbit/s, 64 QAM coherent Nyquist pulse transmission over 150 km

木村光佑, 吉田真人, 岩屋太郎, 葛西恵介, 廣岡俊彦, 中沢正隆

電子情報通信学会大会講演論文集(CD-ROM)　2020　2020

ISSN： 1349-144X
10 Tbit/s QAM Quantum Noise Stream Cipher Coherent Transmission over 160 km.

Masato Yoshida, Takashi Kan, Keisuke Kasai, Toshihiko Hirooka, Masataka Nakazawa

電子情報通信学会大会講演論文集(CD-ROM)　2020　1-3　2020
Publisher: IEEE
ISSN： 1349-144X
R&D of technology for high reliability management of advanced 5G network to various requirements of communication services

新保宏之, 岸洋司, 横山浩之, 石橋功至, 藤井義巳, 中沢正隆, 外山隆之

電子情報通信学会大会講演論文集(CD-ROM)　2020　2020

ISSN： 1349-144X
Experimental and Theoretical Analyses of GAWBS Phase Noise in Multi-Core Fiber for Digital Coherent Transmission.

Naoya Takefushi, Masato Yoshida, Keisuke Kasai, Toshihiko Hirooka, Masataka Nakazawa

電子情報通信学会技術研究報告(Web)　120　(140(OCS2020 4-7))　1-3　2020
Publisher: IEEE
ISSN： 2432-6380
Optical-wireless fully integrated coherent access system toward 6G

中沢正隆

電子情報通信学会大会講演論文集(CD-ROM)　2020　2020

ISSN： 1349-144X
R&D of technology for high reliability management of advanced 5G network to various requirements of communication services

新保宏之, 岸洋司, 横山浩之, 石橋功至, 藤井義巳, 中沢正隆, 外山隆之

電子情報通信学会大会講演論文集(CD-ROM)　2020　2020

ISSN： 1349-144X
160 Gbit/s, 256 QAM bidirectional coherent transmission for mobile fronthaul without backward Rayleigh scattering interference

葛西恵介, 吉田真人, 廣岡俊彦, 岩月勝美, 中沢正隆

電子情報通信学会大会講演論文集(CD-ROM)　2020　2020

ISSN： 1349-144X
Experimental and theoretical analyses of GAWBS noise in multi-core fiber

吉田真人, 竹節直也, 葛西恵介, 廣岡俊彦, 中沢正隆

電子情報通信学会大会講演論文集(CD-ROM)　2020　2020

ISSN： 1349-144X
Suppression of large error floor in 1024 QAM digital coherent transmission by compensating for GAWBS phase noise

Masato Yoshida, Naoya Takefushi, Keisuke Kasai, Toshihiko Hirooka, Masataka Nakazawa

OPTICS EXPRESS　27　(25)　36691-36698　2019/12

DOI： 10.1364/OE.27.036691 　

ISSN： 1094-4087
Single-channel 15.3 Tbit/s, 64 QAM coherent Nyquist pulse transmission over 150 km with a spectral efficiency of 8.3 bit/s/Hz

Masato Yoshida, Kosuke Kimura, Taro Iwaya, Keisuke Kasai, Toshihiko Hirooka, Masataka Nakazawa

OPTICS EXPRESS　27　(20)　28952-28967　2019/09

DOI： 10.1364/OE.27.028952 　

ISSN： 1094-4087
5G R&d activities for high capacity technologies with ultra high-density multi-band and multi-access layered cells

Morihiko Minowa, Hiroyuki Seki, Yukihiko Okumura, Satoshi Suyama, Jun Terada, Satoshi Shigematsu, Yasushi Takatori, Hiroaki Asano, Yukio Hirano, Yasushi Yamao, Fumiyuki Adachi, Masataka Nakazawa

IEEE Vehicular Technology Conference　2019-　2019/04/01
Publisher: Institute of Electrical and Electronics Engineers Inc.
DOI： 10.1109/VTCSpring.2019.8746622 　

ISSN： 1550-2252
5G R&D Activities for High Capacity Technologies with Ultra High-Density Multi-Band and Multi-Access Layered Cells

Morihiko Minowa, Hiroyuki Seki, Yukihiko Okumura, Satoshi Suyama, Jun Terada, Satoshi Shigematsu, Yasushi Takatori, Hiroaki Asano, Yukio Hirano, Yasushi Yamao, Fumiyuki Adachi, Masataka Nakazawa

2019 IEEE 89TH VEHICULAR TECHNOLOGY CONFERENCE (VTC2019-SPRING)　2019

DOI： 10.1109/vtcspring.2019.8746622 　

ISSN： 2577-2465
Experimental and theoretical analyses of GaWBS depolarization noise in digital coherent transmission

Naoya Takefushi, Masato Yoshida, Toshihiko Hirooka, Keisuke Kasai, Masataka Nakazawa

IET Conference Publications　2019　(765)　2019
Publisher: Institution of Engineering and Technology
Demonstration of on-line bi-directional 10-rrhs with an 80 Gbit/s/rrh capacity using 256 QAM WDM coherent transmission for next generation mobile fronthaul

Takashi Kan, Masato Yoshida, Keisuke Kasai, Toshihiko Hirooka, Katsumi Iwatsuki, Masataka Nakazawa

IET Conference Publications　2019　(765)　2019
Publisher: Institution of Engineering and Technology
Sub-Picosecond Optical Switch over Entire C-Band by Using Nonlinear Optical Loop Mirror.

Ryoya Hirata, Toshihiko Hirooka, Masato Yoshida, Masataka Nakazawa

2019 24th OptoElectronics and Communications Conference (OECC) and 2019 International Conference on Photonics in Switching and Computing (PSC)(OECC/PSC)　1-3　2019
Publisher: IEEE
DOI： 10.23919/PS.2019.8817821 　
Dual-Polarization On-Line 256 and 512 QAM Digital Coherent Transmission.

Masato Yoshida, Keisuke Kasai, Toshihiko Hirooka, Masataka Nakazawa

Optical Fiber Communications Conference and Exhibition(OFC)　1-3　2019
Publisher: IEEE
The EDFA Odyssey-From Optical Soliton to Coherent Nyquist Pulse Transmission-

中沢正隆

東北大学電通談話会記録　87　(2)　2019

ISSN： 0385-7719
5G R&D Activities for High Capacity Technologies with Ultra High-Density Multi-Band and Multi-Access Layered Cells.

Morihiko Minowa, Hiroyuki Seki, Yukihiko Okumura, Satoshi Suyama, Jun Terada, Satoshi Shigematsu, Yasushi Takatori, Hiroaki Asano, Yukio Hirano, Yasushi Yamao, Fumiyuki Adachi, Masataka Nakazawa

電子情報通信学会技術研究報告　118　(474(RCS2018 282-338)(Web))　1-5　2019
Publisher: IEEE
DOI： 10.1109/VTCSpring.2019.8746622 　

ISSN： 0913-5685
Wavelength-tunable sub-picosecond optical switch over entire C-band using nonlinear optical loop mirror.

Ryoya Hirata, Toshihiko Hirooka, Masato Yoshida, Masataka Nakazawa

IEICE Electron. Express　16　(23)　20190664-20190664　2019

DOI： 10.1587/elex.16.20190664 　

ISSN： 0913-5685
光時分割多重(OTDM)研究が創出した最先端光技術とその将来展望

中沢正隆

電子情報通信学会誌　102　(8)　2019

ISSN： 0913-5693
GAWBS Noise Characteristics in Digital Coherent Transmission in Various Optical Fibers.

Naoya Takefushi, Masato Yoshida, Keisuke Kasai, Toshihiko Hirooka, Masataka Nakazawa

電子情報通信学会技術研究報告　119　(93(OCS2019 10-19)](Web))　1-3　2019
Publisher: IEEE
DOI： 10.23919/PS.2019.8818113 　

ISSN： 0913-5685
50.4 Tbit/s, L-band 480 ch-WDM, 128 QAM-160 km Digital Coherent Optical Transmission Using an Injection-locked Homodyne Receiver

管貴志, 葛西恵介, 吉田真人, 廣岡俊彦, 中沢正隆

電子情報通信学会技術研究報告　119　(93(OCS2019 10-19)](Web))　2019

ISSN： 0913-5685
通信波長帯光源を用いた小型絶対重力計TAG-1の運用と系統誤差評価

新谷昌人, 葛西恵介, 吉田真人, 中沢正隆, 田村良明, 坪川恒也

日本測地学会講演会要旨　132nd　2019
次世代モバイルフロントホール用256QAMオンライン双方向コヒーレント伝送

吉田真人, 管貴志, 葛西恵介, 廣岡俊彦, 岩月勝美, 中沢正隆

電子情報通信学会大会講演論文集(CD-ROM)　2019　2019

ISSN： 1349-144X
リアルタイム偏波多重256~512QAMデジタルコヒーレント光伝送

吉田真人, 葛西恵介, 廣岡俊彦, 中沢正隆

電子情報通信学会大会講演論文集(CD-ROM)　2019　2019

ISSN： 1349-144X
256QAM WDMオンライン双方向コヒーレント伝送を用いた次世代C-RANモバイルフロントホール

管貴志, 吉田真人, 葛西恵介, 廣岡俊彦, 岩月勝美, 中沢正隆

電子情報通信学会大会講演論文集(CD-ROM)　2019　2019

ISSN： 1349-144X
5G実現に向けた超高密度マルチバンド・マルチアクセス多層セル構成による大容量化技術の研究開発

箕輪守彦, 関宏之, 奥村幸彦, 須山聡, 寺田純, 重松智志, 鷹取泰司, 浅野弘明, 平野幸男, 山尾泰, 安達文幸, 中沢正隆

電子情報通信学会大会講演論文集(CD-ROM)　2019　2019

ISSN： 1349-144X
デジタルコヒーレント光伝送における各種ファイバのGAWBS雑音特性

竹節直也, 吉田真人, 葛西恵介, 廣岡俊彦, 中沢正隆

電子情報通信学会大会講演論文集(CD-ROM)　2019　2019

ISSN： 1349-144X
注入同期法を用いた200Gbit/s,10Gsymbol/s-1024QAM160kmデジタルコヒーレント光伝送

葛西恵介, 岡本聖司, 吉田真人, 中沢正隆

電子情報通信学会大会講演論文集(CD-ROM)　2019　2019

ISSN： 1349-144X
高精度光位相制御技術を用いた超多値QAMコヒーレント光伝送

吉田真人, 葛西恵介, 中沢正隆

電子情報通信学会大会講演論文集(CD-ROM)　2019　2019

ISSN： 1349-144X
50.4Tbit/s,L-band WDM128QAM-160kmコヒーレント光伝送

管貴志, 葛西恵介, 吉田真人, 廣岡俊彦, 中沢正隆

電子情報通信学会大会講演論文集(CD-ROM)　2019　2019

ISSN： 1349-144X
非線形光ループミラーを用いたフルCバンドサブピコ秒光スイッチ

平田綾也, 廣岡俊彦, 吉田真人, 中沢正隆

電子情報通信学会大会講演論文集(CD-ROM)　2019　2019

ISSN： 1349-144X
線幅8kHz,C+Lバンド波長可変LDの波長可変特性

葛西恵介, 中沢正隆, 友松泰則, 遠藤尚

電子情報通信学会大会講演論文集(CD-ROM)　2019　2019

ISSN： 1349-144X
Real-Time 256 QAM Bi-directional Coherent Transmission in Next Generation Mobile Fronthaul. Peer-reviewed

Masato Yoshida, Takashi Kan, Keisuke Kasai, Toshihiko Hirooka, Masataka Nakazawa

電子情報通信学会技術研究報告　117　(423(OCS2017 67-78))　1-3　2019
Publisher: Institute of Electrical and Electronics Engineers Inc.
DOI： 10.23919/PS.2019.8817867 　

ISSN： 0913-5685
Single-channel 10.2 Tbit/s (2.56 Tbaud) optical Nyquist pulse transmission over 300 km

Toshihiko Hirooka, Ryoya Hirata, Jianping Wang, Masato Yoshida, Masataka Nakazawa

OPTICS EXPRESS　26　(21)　27221-27236　2018/10

DOI： 10.1364/OE.26.027221 　

ISSN： 1094-4087
Single-channel 7.68 Tbit/s, 64 QAM coherent Nyquist pulse transmission over 150 km with a spectral efficiency of 9.7 bit/s/Hz

Kosuke Kimura, Junpei Nitta, Masato Yoshida, Keisuke Kasai, Toshihiko Hirooka, Masataka Nakazawa

OPTICS EXPRESS　26　(13)　17418-17428　2018/06

DOI： 10.1364/OE.26.017418 　

ISSN： 1094-4087
Single-channel 200 Gbit/s, 10 Gsymbol/s-1024 QAM injection-locked coherent transmission over 160 km with a pilot-assisted adaptive equalizer

Yixin Wang, Seiji Okamoto, Keisuke Kasai, Masato Yoshida, Masataka Nakazawa

OPTICS EXPRESS　26　(13)　17015-17024　2018/06

DOI： 10.1364/OE.26.017015 　

ISSN： 1094-4087
A New Optical Phase-Locked System between Ultrashort Pulses for 640 Gbaud Nyquist OTDM Coherent QAM Transmission Peer-reviewed

Kosuke Kimura, Junpei Nitta, Masato Yoshida, Keisuke Kasai, Toshihiko Hirooka, Masataka Nakazawa

European Conference on Optical Communication, ECOC　2017-　1-3　2018/04/24
Publisher: Institute of Electrical and Electronics Engineers Inc.
DOI： 10.1109/ECOC.2017.8345851 　
Single-carrier 552 Gbit/s, 46 Gbaud 64 QAM Coherent Transmission over 100 km with Co-propagating 10 Gbit/s-OOK Signals Through a Deployed ROADM Network Peer-reviewed

Keisuke Kasai, Toshihiko Hirooka, Masato Yoshida, Masataka Nakazawa, Masaki Shiraiwa, Yoshinari Awaji, Naoya Wada

European Conference on Optical Communication, ECOC　2017-　1-3　2018/04/24
Publisher: Institute of Electrical and Electronics Engineers Inc.
DOI： 10.1109/ECOC.2017.8345944 　
Observation of guided acoustic-wave Brillouin scattering noise and its compensation in digital coherent optical fiber transmission

Masataka Nakazawa, Masato Yoshida, Masaki Terayama, Seiji Okamoto, Keisuke Kasai, Toshihiko Hirooka

OPTICS EXPRESS　26　(7)　9165-9181　2018/04

DOI： 10.1364/OE.26.009165 　

ISSN： 1094-4087
8 kHz linewidth, 50 mW output, full C-band wavelength tunable DFB LD array with self-optical feedback Peer-reviewed

Keisuke Kasai, Masataka Nakazawa, Mitsuteru Ishikawa, Hiroyuki Ishii

Optics Express　26　(5)　5675-5685　2018/03/05
Publisher: OSA - The Optical Society
DOI： 10.1364/OE.26.005675 　

ISSN： 1094-4087
10.16-Peta-B/s Dense SDM/WDM Transmission Over 6-Mode 19-Core Fiber Across the C plus L Band Peer-reviewed

Daiki Soma, Yuta Wakayama, Shohei Beppu, Seiya Sumita, Takehiro Tsuritani, Tetsuya Hayashi, Takuji Nagashima, Masato Suzuki, Masato Yoshida, Keisuke Kasai, Masataka Nakazawa, Hidenori Takahashi, Koji Igarashi, Itsuro Morita, Masatoshi Suzuki

JOURNAL OF LIGHTWAVE TECHNOLOGY　36　(6)　1362-1368　2018/03

DOI： 10.1109/JLT.2018.2799380 　

ISSN： 0733-8724

eISSN： 1558-2213
50.4 Tbit/s, 128 QAM L-band WDM Injection-locked Coherent Transmission over 160 km with Spectral Efficiency of 10.5 bit/s/Hz

Takashi Kan, Keisuke Kasai, Masato Yoshida, Toshihiko Hirooka, Masataka Nakazawa

23RD OPTO-ELECTRONICS AND COMMUNICATIONS CONFERENCE (OECC2018)　2018

ISSN： 2166-8884

eISSN： 2166-8892
200 Gbit/s, 10 Gsymbol/s-1024 QAM Injection Locked Coherent Transmission over 160 km with a Pilot-assisted Adaptive Equalizer

Keisuke Kasai, Yixing Wang, Seiji Okamoto, Masato Yoshida, Masataka Nakazawa

23RD OPTO-ELECTRONICS AND COMMUNICATIONS CONFERENCE (OECC2018)　2018

ISSN： 2166-8884

eISSN： 2166-8892
Single-Channel 7.68 Tbit/s, 64 QAM Coherent Nyquist Pulse Transmission over 150 km with a Spectral Efficiency of 9.7 bit/s/Hz

Kosuke Kimura, Junpei Nitta, Masato Yoshida, Keisuke Kasai, Toshihiro Hirooka, Masataka Nakazawa

23RD OPTO-ELECTRONICS AND COMMUNICATIONS CONFERENCE (OECC2018)　2018

ISSN： 2166-8884

eISSN： 2166-8892
Reverse Phase Modulation Technique for GAWBS Noise Error Floor Elimination in 1024 QAM-160 km Digital Coherent Transmission

Masato Yoshida, Naoya Takefushi, Masaki Terayama, Keisuke Kasai, Toshihiko Hirooka, Masataka Nakazawa

23RD OPTO-ELECTRONICS AND COMMUNICATIONS CONFERENCE (OECC2018)　2018

ISSN： 2166-8884

eISSN： 2166-8892
4096 QAM (72 Gbit/s) Single-Carrier Coherent Optical Transmission with a Potential SE of 15.8 bit/s/Hz in All-Raman Amplified 160 km Fiber Link.

Masaki Terayama, Seiji Okamoto, Keisuke Kasai, Masato Yoshida, Masataka Nakazawa

Optical Fiber Communications Conference and Exposition(OFC)　1-3　2018
Publisher: IEEE
Experimental and Numerical Comparison of Probabilistically-Shaped 4096 QAM and Uniformly-Shaped 1024 QAM in All-Raman Amplified 160 km Transmission.

Seiji Okamoto, Masaki Terayama, Masato Yoshida, Keisuke Kasai, Toshihiko Hirooka, Masataka Nakazawa

Optical Fiber Communications Conference and Exposition(OFC)　1-3　2018
Publisher: IEEE
Secure Transmission using QAM Quantum Noise Stream Cipher with Continuous Variable QKD.

Masataka Nakazawa, Masato Yoshida, Takuya Hirano

Optical Fiber Communications Conference and Exposition(OFC)　1-3　2018
Publisher: IEEE
Observation of Guided Acoustic-Wave Brillouin Scattering and its Digital Compensation in Coherent QAM Transmission.

Masataka Nakazawa, Masaki Terayama, Seiji Okamoto, Masato Yoshida, Keisuke Kasai, Toshihiko Hirooka

Optical Fiber Communications Conference and Exposition(OFC)　1-3　2018
Publisher: IEEE
Backward-Rayleigh-Scattering Suppressed 160 Gbit/s 256 QAM Injection-Locked Bidirectional Coherent Transmission for Next Generation Mobile Fronthaul.

Keisuke Kasai, Masato Yoshida, Toshihiko Hirooka, Katsumi Iwatsuki, Masataka Nakazawa

European Conference on Optical Communication(ECOC)　1-3　2018
Publisher: IEEE
DOI： 10.1109/ECOC.2018.8535196 　
単一チャンネル7.68Tbit/s-150km,64QAMコヒーレントナイキストパルス伝送

新田純平, 木村光佑, 吉田真人, 葛西恵介, 廣岡俊彦, 中沢正隆

電子情報通信学会大会講演論文集(CD-ROM)　2018　2018

ISSN： 1349-144X
4096QAM(72Gbit/s)-160kmディジタルコヒーレント光伝送

寺山雅樹, 岡本聖司, 葛西恵介, 吉田真人, 中沢正隆

電子情報通信学会大会講演論文集(CD-ROM)　2018　2018

ISSN： 1349-144X
光注入同期法を用いた次世代モバイルフロントホール用160Gbit/s,256QAMデジタルコヒーレント伝送

葛西恵介, WANG Yixin, 吉田真人, 廣岡俊彦, 岩月勝美, 中沢正隆

電子情報通信学会大会講演論文集(CD-ROM)　2018　2018

ISSN： 1349-144X
空間多重光通信技術の最前線空間多重伝送における光計測-マルチチャネルOTDRによるMCFおよびFMFのモード結合の測定-

吉田真人, 中沢正隆

Optronics　(440)　2018

ISSN： 0286-9659
空間多重光通信技術の最前線 EXAT研究会/3M技術の10年を振り返って

中沢正隆, 淡路祥成

Optronics　(440)　2018

ISSN： 0286-9659
注入同期法を用いた12bit/s/Hz,58.2Tbit/s,256QAM-160km CバンドWDM伝送

管貴志, 葛西恵介, 吉田真人, 廣岡俊彦, 中沢正隆

電子情報通信学会大会講演論文集(CD-ROM)　2018　2018

ISSN： 1349-144X
単一チャネル10.2Tbit/s-300km光ナイキストパルス伝送

平田綾也, WANG Jianping, 廣岡俊彦, 吉田真人, 中沢正隆

電子情報通信学会大会講演論文集(CD-ROM)　2018　2018

ISSN： 1349-144X
GAWBS位相雑音補償による1024QAMコヒーレント光伝送におけるエラーフロアの抑制

吉田真人, 竹節直也, 葛西恵介, 廣岡俊彦, 中沢正隆

電子情報通信学会大会講演論文集(CD-ROM)　2018　2018

ISSN： 1349-144X
自己光帰還法を用いた線幅8kHz,出力50mW,C帯波長可変DFB LD

葛西恵介, 中沢正隆

電子情報通信学会大会講演論文集(CD-ROM)　2018　2018

ISSN： 1349-144X
Oscillation characteristics of a narrow linewidth DFB LD array with an optical feedback method

葛西恵介, 中沢正隆

電子情報通信学会技術研究報告　118　(186(EMD2018 20-36))　2018

ISSN： 0913-5685
PS-4096QAM信号と1024QAM信号の160km伝送特性比較

岡本聖司, 岡本聖司, 寺山雅樹, 吉田真人, 葛西恵介, 廣岡俊彦, 中沢正隆

電子情報通信学会大会講演論文集(CD-ROM)　2018　2018

ISSN： 1349-144X
空間分割多重光通信技術の進展 10ペタビット級光伝送実験の成功

相馬大樹, 若山雄太, 別府翔平, 角田聖也, 釣谷剛宏, 林哲也, 永島拓志, 鈴木雅人, 吉田真人, 葛西恵介, 中沢正隆, 高橋英憲, 五十嵐浩司, 五十嵐浩司, 森田逸郎, 鈴木正敏

O plus E　(463)　2018

ISSN： 0911-5943
光ナイキストパルスを用いた単一チャネル10Tbit/s級超高速伝送

廣岡俊彦, 吉田真人, 中沢正隆

電子情報通信学会大会講演論文集(CD-ROM)　2018　2018

ISSN： 1349-144X
Single-Channel 10.2 Tbit/s PDM-DQPSK Nyquist Pulse Transmission over 300 km.

Toshihiko Hirooka, Ryoya Hirata, Jianping Wang, Masato Yoshida, Masataka Nakazawa

電子情報通信学会技術研究報告　118　(238(OFT2018 13-51)(Web))　1-3　2018
Publisher: IEEE
DOI： 10.1109/ECOC.2018.8535329 　

ISSN： 0913-5685
12 bit/s/Hz, 58.2 Tbit/s, 256 QAM-160 km C-band WDM Transmission Using an Injection Locking Technique

管貴志, 葛西恵介, 吉田真人, 廣岡俊彦, 中沢正隆

電子情報通信学会技術研究報告　118　(238(OFT2018 13-51)(Web))　2018

ISSN： 0913-5685
Observation of GAWBS Noise and Development of its Compensation Technique in Digital Coherent Optical Transmission

竹節直也, 吉田真人, 葛西恵介, 廣岡俊彦, 中沢正隆

電子情報通信学会技術研究報告　118　(238(OFT2018 13-51)(Web))　2018

ISSN： 0913-5685
Single-channel 7.68 Tbit/s, 64 QAM coherent Nyquist pulse transmission over 150 km with a spectral efficiency of 9.7 bit/s/Hz

木村光佑, 新田純平, 吉田真人, 葛西恵介, 廣岡俊彦, 中沢正隆

電子情報通信学会技術研究報告　118　(238(OFT2018 13-51)(Web))　2018

ISSN： 0913-5685
Injection-locked Homodyne Detection for Higher-order QAM Transmission. Invited Peer-reviewed

Keisuke Kasai, Yixin Wang, Masato Yoshida, Toshihiko Hirooka, Masataka Nakazawa

European Conference on Optical Communication (ECOC 2016)　1-3　2018
Publisher: IEEE
Narrow Linewidth Tunable DFB Laser Array Integrated With Optical Feedback Planar Lightwave Circuit (PLC) Peer-reviewed

Hiroyuki Ishii, Naoki Fujiwara, Kei Watanabe, Shigeru Kanazawa, Mikitaka Itoh, Hirokazu Takenouchi, Yutaka Miyamoto, Keisuke Kasai, Masataka Nakazawa

IEEE JOURNAL OF SELECTED TOPICS IN QUANTUM ELECTRONICS　23　(6)　1501007　2017/11

DOI： 10.1109/JSTQE.2017.2693021 　

ISSN： 1077-260X

eISSN： 1558-4542
1.5 mu m, mode-hop-free full C-band wavelength tunable laser diode with a linewidth of 8 kHz and a RIN of-130 dB/Hz and its extension to the L- band Peer-reviewed

Keisuke Kasai, Masataka Nakazawa, Yasunori Tomomatsu, Takashmi Endo

OPTICS EXPRESS　25　(18)　22113-22124　2017/09

DOI： 10.1364/OE.25.022113 　

ISSN： 1094-4087
42.3 Tbit/s, 18 Gbaud 64 QAM WDM coherent transmission over 160 km in the C-band using an injection-locked homodyne receiver with a spectral efficiency of 9 bit/s/Hz Peer-reviewed

Takashi Kan, Keisuke Kasai, Masato Yoshida, Masataka Nakazawa

OPTICS EXPRESS　25　(19)　22726-22737　2017/09

DOI： 10.1364/OE.25.022726 　

ISSN： 1094-4087
Discrete solitons in optical fiber systems with large pre-dispersion Peer-reviewed

Shiva Kumar, Masataka Nakazawa

OPTICS EXPRESS　25　(17)　19923-19945　2017/08

DOI： 10.1364/OE.25.019923 　

ISSN： 1094-4087
QAM Quantum Noise Stream Cipher Transmission Over 100 km With Continuous Variable Quantum Key Distribution Peer-reviewed

Masataka Nakazawa, Masato Yoshida, Toshihiko Hirooka, Keisuke Kasai, Takuya Hirano, Tsubasa Ichikawa, Ryo Namiki

IEEE JOURNAL OF QUANTUM ELECTRONICS　53　(4)　8000316　2017/08

DOI： 10.1109/JQE.2017.2708523 　

ISSN： 0018-9197

eISSN： 1558-1713
Low-loss and reflection-free fused type fan-out device for 7-core fiber based on a bundled structure Peer-reviewed

Masato Yoshida, Toshihiko Hirooka, Masataka Nakazawa

OPTICS EXPRESS　25　(16)　18817-18826　2017/08

DOI： 10.1364/OE.25.018817 　

ISSN： 1094-4087
Invention Of LD-pumped EDFA And Their Applications From Soliton To Coherent Nyquist Pulse Transmission Invited Peer-reviewed

M. Nakazawa

the Pacific Rim Conference on Lasers and Electro‐Optics (CLEO-PR 2017)　1-3F-2　2017/08
1024 QAM Coherent Optical Transmission In 31 Km-long, 19-core Fiber With Low Crosstalk And Large Effective Area Peer-reviewed

M. Yoshida, K. Kasai, T. Hirooka, M. Nakazawa, K. Imamura, R. Sugizaki

Opto-Electronics and Communications Conference (OECC 2017)　3-1K-2　2017/08
Recent Progress on Ultra-High Capacity Optical Transmission using Multi-Level, Multi-Core, and Multi-Mode Techniques Invited Peer-reviewed

M. Nakazawa

the 24th General Congress of International Commission for Optics(ICO-24)　Tu2E-01　2017/08
Progress on 3M Communication Systems Invited Peer-reviewed

M. Nakazawa

International Symposium on Ultrafast Photonic Technologies (ISUPT 2017)　Invited talk　2017/07
Single-channel 3.84 Tbit/s, 64 QAM coherent Nyquist pulse transmission over 150 km with a spectral efficiency of 10.6 bit/s/Hz Peer-reviewed

Junpei Nitta, Masato Yoshida, Kosuke Kimura, Keisuke Kasai, Toshihiko Hirooka, Masataka Nakazawa

OPTICS EXPRESS　25　(13)　15199-15207　2017/06

DOI： 10.1364/OE.25.015199 　

ISSN： 1094-4087
New Optical Phase-Locking System Based on Mode-Locked Fiber Laser for 640 Gbaud Coherent Nyquist QAM Transmission

Tohoku-Section Joint Convention Record of Institutes of Electrical and Information Engineers, Japan　2017　22-22　2017
Publisher: Organizing Committee of Tohoku-Section Joint Convention of Institutes of Electrical and Information Engineers, Japan
DOI： 10.11528/tsjc.2017.0_22 　
A full C-band wavelength tunable laser diode with narrow linewidth and low intensity noise characteristics

葛西恵介, 中沢正隆, 友松泰則, 遠藤尚

電子情報通信学会技術研究報告　117　(194(OPE2017 48-67))　2017

ISSN： 0913-5685
単一チャネル3.84Tbit/s,64QAMコヒーレントナイキストパルス信号の150km伝送

新田純平, 木村光佑, 吉田真人, 葛西恵介, 廣岡俊彦, 中沢正隆

電子情報通信学会大会講演論文集(CD-ROM)　2017　2017

ISSN： 1349-144X
光注入同期を用いた42.3Tbit/s,C-band WDM64QAM-160kmコヒーレント伝送

管貴志, 葛西恵介, 吉田真人, 中沢正隆

電子情報通信学会大会講演論文集(CD-ROM)　2017　2017

ISSN： 1349-144X
A 40 GHz, 770 fs regeneratively mode-locked erbium fiber laser operating at 1.6 µm. Peer-reviewed

Koudai Harako, Masato Yoshida, Toshihiko Hirooka, Masataka Nakazawa

IEICE Electron. Express　14　(19)　20170829-20170829　2017

DOI： 10.1587/elex.14.20170829 　

ISSN： 1349-2543
Single-Carrier 216 Gbit/s, 12 Gsymbol/s 512 QAM Coherent Transmission over 160 km with Injection-locked Homodyne Detection Peer-reviewed

Yixin Wang, Keisuke Kasai, Masato Yoshida, Masataka Nakazawa

2017 OPTICAL FIBER COMMUNICATIONS CONFERENCE AND EXHIBITION (OFC)　Tu2E.1　2017
Full C-band, Mode-Hop-Free Wavelength-Tunable Laser Diode with a Linewidth of 8 kHz and a RIN of-130 dB/Hz Peer-reviewed

Keisuke Kasai, Masataka Nakazawa, Yasunori Tomomatsu, Takashi Endo

2017 OPTICAL FIBER COMMUNICATIONS CONFERENCE AND EXHIBITION (OFC)　W1E.2　2017
Fabrication of Multi Core Fiber by Using Slurry Casting Method Peer-reviewed

Jun Yamamoto, Tamotsu Yajima, Yusuke Kinoshita, Futoshi Ishii, Masato Yoshida, Toshihiko Hirooka, Masataka Nakazawa

2017 OPTICAL FIBER COMMUNICATIONS CONFERENCE AND EXHIBITION (OFC)　Th1H.5　2017
Single-Channel 3.84 Tbit/s, 64 QAM Coherent Nyquist Pulse Transmission over 150km with Frequency-Stabilized and Mode-Locked Laser Peer-reviewed

Masato Yoshida, Junpei Nitta, Kosuke Kimura, Keisuke Kasai, Toshihiko Hirooka, Masataka Nakazawa

2017 OPTICAL FIBER COMMUNICATIONS CONFERENCE AND EXHIBITION (OFC)　Th2A.52　2017
42.3-Tbits/s, 18-Gbaud 64QAM WDM Coherent Transmission of 160 km over Full C-based using an Injection Locking Technique with a Spectral Efficiency of 9 bit/s/Hz Peer-reviewed

Takashi Kan, Keisuke Kasai, Masato Yoshida, Masataka Nakazawa

2017 OPTICAL FIBER COMMUNICATIONS CONFERENCE AND EXHIBITION (OFC)　Th3F.5　2017
40 GHz, 770 fs harmonically and regeneratively FM mode-locked erbium fiber laser in L-band Peer-reviewed

Koudai Harako, Masato Yoshida, Toshihiko Hirooka, Masataka Nakazawa

Optics InfoBase Conference Papers　2017　SM4L.2　2017
Publisher: OSA - The Optical Society
DOI： 10.1364/CLEO_SI.2017.SM4L.2 　
Subpicosecond coherent Nyquist pulse generation for 1-Tbaud transmission using a C2H2 frequency-stabilized CW Laser and a 40 GHz optical comb generator Peer-reviewed

Daiki Suzuki, Keisuke Kasai, Toshihiko Hirooka, Masataka Nakazawa

Optics InfoBase Conference Papers　2017　SM2L.5　2017
Publisher: OSA - The Optical Society
DOI： 10.1364/CLEO_SI.2017.SM2L.5 　
Single-channel 5.12 Tbit/s (1.28 Tbaud) DQPSK transmission over 300 km using non-coherent Nyquist pulses Peer-reviewed

Daiki Suzuki, Koudai Harako, Toshihiko Hirooka, Masataka Nakazawa

OPTICS EXPRESS　24　(26)　29683-29691　2016/12

DOI： 10.1364/OE.24.029682 　

ISSN： 1094-4087
440 fs, 9.2 GHz regeneratively mode-locked erbium fiber laser with a combination of higher-order solitons and a SESAM saturable absorber Peer-reviewed

Toshihiko Hirooka, Kazunari Tokuhira, Masato Yoshida, Masataka Nakazawa

OPTICS EXPRESS　24　(21)　24255-24264　2016/10

DOI： 10.1364/OE.24.024255 　

ISSN： 1094-4087
1.55 mu m hydrogen cyanide optical frequency-stabilized and 10 GHz repetition-rate-stabilized mode-locked fiber laser Peer-reviewed

Masato Yoshida, Kazuki Yoshida, Keisuke Kasai, Masataka Nakazawa

OPTICS EXPRESS　24　(21)　24287-24296　2016/10

DOI： 10.1364/OE.24.024287 　

ISSN： 1094-4087
Roll-off factor dependence of Nyquist pulse transmission Peer-reviewed

Koudai Harako, Daiki Suzuki, Toshihiko Hirooka, Masataka Nakazawa

OPTICS EXPRESS　24　(19)　21986-21994　2016/09

DOI： 10.1364/OE.24.021986 　

ISSN： 1094-4087
320 Gbit/s, 20 Gsymbol/s 256 QAM coherent transmission over 160 km by using injection-locked local oscillator Peer-reviewed

Yixin Wang, Keisuke Kasai, Masato Yoshida, Masataka Nakazawa

OPTICS EXPRESS　24　(19)　22088-22096　2016/09

DOI： 10.1364/OE.24.022088 　

ISSN： 1094-4087
Single-channel 5.12 Tbit/s (1.28 Tbaud) DQPSK Transmission over 300 km Using Non-coherent Nyquist Pulses Peer-reviewed

D. Suzuki, K. Harako, T. Hirooka, M. Nakazawa

European Conference on Optical Communication (ECOC 2016)　W.4.P1.SC5.49　2016/09
552 Gbit/s, 46 Gbaud, 64 QAM Coherent Transmission over 160 km with Simple LD-based Injection-locked Homodyne Detection Peer-reviewed

K. Kasai, M. Yoshida, M. Nakazawa

European Conference on Optical Communication (ECOC 2016)　W.4.P1.SC5.51　2016/09
Real-time 70 Gbit/s, 128 QAM Quantum Noise Stream Cipher Transmission over 100 km with Secret Keys Delivered by Continuous Variable Quantum Key Distribution System Peer-reviewed

M. Nakazawa, M. Yoshida, T. Hirooka, K. Kasai, T Hirano

European Conference on Optical Communication (ECOC 2016)　W.4.P1.SC5.59　2016/09
A Non-Perturbative Mode-Locking Theory of the Nyquist Laser With a Dirichlet Kernel Solution Peer-reviewed

Masataka Nakazawa, Toshihiko Hirooka

IEEE JOURNAL OF QUANTUM ELECTRONICS　52　(8)　1300113　2016/08

DOI： 10.1109/JQE.2016.2584585 　

ISSN： 0018-9197

eISSN： 1558-1713
A 1.55 mu m, 271 fs and 1.07 mu m, 294 fs simultaneously mode-locked Er- and Yb-doped fiber laser with a single SWNT/PVA saturable absorber Peer-reviewed

Masatoshi Nakao, Masato Yoshida, Toshihiko Hirooka, Masataka Nakazawa

IEICE ELECTRONICS EXPRESS　13　(14)　20160515　2016/07

DOI： 10.1587/elex.13.20160515 　

ISSN： 1349-2543
1024 QAM, 7-core fiber/multi-core EDFA transmission over 100 km with an aggregated spectral efficiency of 109 bit/s/Hz Peer-reviewed

M. Yoshida, K. Kasai, T. Hirooka, M. Nakazawa

2016 Opto-Electronics and Communications Conference (OECC2016)　MB2-5　2016/07
“Multi” is everywhere Invited Peer-reviewed

M. Nakazawa

Conference on Lasers and Electro-Optics (CLEO 2016)　plenary talk　2016/06
Fused type fan-out device for multi-core fiber based on bundled structure Peer-reviewed

M. Yoshida, T. Hirooka, M. Nakazawa

Optical Fiber Communication Conference (OFC2016)　Tu3I.2　2016/03
Mode coupling measurement at a splice point between few-mode fibers using a synchronous multi-channel OTDR Peer-reviewed

M. Yoshida, T. Hirooka, M. Nakazawa

Optical Fiber Communication Conference (OFC2016)　2016　(2)　Th1J.4-452　2016/03
Publisher: The Institute of Electronics, Information and Communication Engineers
Mode locking theory of the Nyquist laser Peer-reviewed

Masataka Nakazawa, Toshihiko Hirooka

OPTICS EXPRESS　24　(5)　4981-4995　2016/03

DOI： 10.1364/OE.24.004981 　

ISSN： 1094-4087
295 mW output, frequency-stabilized erbium silica fiber laser with a linewidth of 5 kHz and a RIN of-120 dB/Hz Peer-reviewed

Keisuke Kasai, Masato Yoshida, Masataka Nakazawa

OPTICS EXPRESS　24　(3)　2737-2748　2016/02

DOI： 10.1364/OE.24.002737 　

ISSN： 1094-4087
Ultra-multilevel digital coherent optical transmission employing a narrow linewidth laser, an optical phase-locked loop circuit and injection-locking scheme Invited Peer-reviewed

K. Kasai, M. Nakazawa

The Review of Laser Engineering (in Japanese)　44　(2)　106-110　2016/02
Single-Channel 1.92 Tbit/s, 64 QAM Coherent Nyquist Orthogonal TDM Transmission With a Spectral Efficiency of 10.6 Bit/s/Hz

David Odeke Otuya, Keisuke Kasai, Toshihiko Hirooka, Masataka Nakazawa

JOURNAL OF LIGHTWAVE TECHNOLOGY　34　(2)　768-775　2016/01/15

DOI： 10.1109/JLT.2015.2468580 　

ISSN： 0733-8724

eISSN： 1558-2213
Single-channel 40 Gbit/s digital coherent QAM quantum noise stream cipher transmission over 480 km

Masato Yoshida, Toshihiko Hirooka, Keisuke Kasai, Masataka Nakazawa

OPTICS EXPRESS　24　(1)　652-661　2016/01/11

DOI： 10.1364/OE.24.000652 　

ISSN： 1094-4087
Injection-locked homodyne detection system for higher-order QAM digital coherent transmission

Keisuke Kasai, Masato Yoshida, Toshihiko Hirooka, Masataka Nakazawa

European Conference on Optical Communication, ECOC　34-36　2016
Publisher: Institute of Electrical and Electronics Engineers Inc.
Preliminary experiment on 4096 QAM coherent optical transmission at 1.5 Gsymbol/s over 160 km

Tohoku-Section Joint Convention Record of Institutes of Electrical and Information Engineers, Japan　2016　7-7　2016
Publisher: Organizing Committee of Tohoku-Section Joint Convention of Institutes of Electrical and Information Engineers, Japan
DOI： 10.11528/tsjc.2016.0_7 　
45.12 Tbit/s, 235 ch-WDM 64 QAM Coherent Transmission over 160 km with an Injection Locked Homodyne Receiver

Tohoku-Section Joint Convention Record of Institutes of Electrical and Information Engineers, Japan　2016　6-6　2016
Publisher: Organizing Committee of Tohoku-Section Joint Convention of Institutes of Electrical and Information Engineers, Japan
DOI： 10.11528/tsjc.2016.0_6 　
A Mode Locking Theory of the Nyquist Laser Peer-reviewed

Masataka Nakazawa, Toshihiko Hirooka

2016 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO)　2016

ISSN： 2160-9020
Fabrication of OH-free, single-mode fiber by using slurry casting and rod-in-tube method Peer-reviewed

Tamotsu Yajima, Jun Yamamoto, Yusuke Kinoshita, Futoshi Ishii, Toshihiko Hirooka, Masato Yoshida, Masataka Nakazawa

IEICE ELECTRONICS EXPRESS　13　(1)　2016/01

DOI： 10.1587/elex.12.20151005 　

ISSN： 1349-2543
Single-channel 40 Gbit/s digital coherent QAM quantum noise stream cipher transmission over 480 km Peer-reviewed

Masato Yoshida, Toshihiko Hirooka, Keisuke Kasai, Masataka Nakazawa

OPTICS EXPRESS　24　(1)　652-661　2016/01

DOI： 10.1364/OE.24.000652 　

ISSN： 1094-4087
Single-Channel 1.92 Tbit/s, 64 QAM Coherent Nyquist Orthogonal TDM Transmission With a Spectral Efficiency of 10.6 Bit/s/Hz Peer-reviewed

David Odeke Otuya, Keisuke Kasai, Toshihiko Hirooka, Masataka Nakazawa

JOURNAL OF LIGHTWAVE TECHNOLOGY　34　(2)　768-775　2016/01

DOI： 10.1109/JLT.2015.2468580 　

ISSN： 0733-8724

eISSN： 1558-2213
Optical and wireless-integrated next-generation access network based on coherent technologies Invited Peer-reviewed

Toshihiko Hirooka, Masato Yoshida, Keisuke Kasai, Masataka Nakazawa

BROADBAND ACCESS COMMUNICATION TECHNOLOGIES X　9772　9772-2　2016

DOI： 10.1117/12.2211860 　

ISSN： 0277-786X
A 295 mW Output, HCN Frequency-Stabilized CW Erbium Silica Fiber Laser with a Linewidth of 5 kHz and a RIN of-120 dB/Hz Peer-reviewed

Keisuke Kasai, Masato Yoshida, Masataka Nakazawa

2016 OPTICAL FIBER COMMUNICATIONS CONFERENCE AND EXHIBITION (OFC)　W3E.1　2016
A 440 fs, 9.2 GHz Hybrid Mode-Locked Erbium Fiber Laser with a Combination of Higher-Order Solitons and a SESAM Saturable Absorber Peer-reviewed

Toshihiko Hirooka, Kazunari Tokuhira, Masato Yoshida, Masataka Nakazawa

2016 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO)　STu1P.4　2016

ISSN： 2160-9020
A 0.95 ps, 10 GHz, 60 mW HCN Frequency-Stabilized and Mode-Locked Fiber Laser at 1.55 mu m Peer-reviewed

Masato Yoshida, Kazuki Yoshida, Keisuke Kasai, Masataka Nakazawa

2016 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO)　STu1P.3　2016

ISSN： 2160-9020
Ultrahigh Speed and High Spectral Efficiency Transmission Using Optical Nyquist Pulses Invited Peer-reviewed

Masataka Nakazawa

2016 21ST OPTOELECTRONICS AND COMMUNICATIONS CONFERENCE (OECC) HELD JOINTLY WITH 2016 INTERNATIONAL CONFERENCE ON PHOTONICS IN SWITCHING (PS)　MB1-1　2016
Roll-off Factor Dependence of System Performance in 1.28 Tbit/s/ch-525 km Nyquist Pulse Transmission Peer-reviewed

Koudai Harako, Daiki Suzuki, Toshihiko Hirooka, Masataka Nakazawa

2016 21ST OPTOELECTRONICS AND COMMUNICATIONS CONFERENCE (OECC) HELD JOINTLY WITH 2016 INTERNATIONAL CONFERENCE ON PHOTONICS IN SWITCHING (PS)　MB1-2　2016
320 Gbit/s, 256 QAM LD-based Coherent Transmission over 160 km with an Injection-locked Homodyne Detection Technique Peer-reviewed

Yixin Wang, Keisuke Kasai, Masato Yoshida, Masataka Nakazawa

2016 21ST OPTOELECTRONICS AND COMMUNICATIONS CONFERENCE (OECC) HELD JOINTLY WITH 2016 INTERNATIONAL CONFERENCE ON PHOTONICS IN SWITCHING (PS)　ThB3-3　2016
First demonstration of digital coherent transmission in a deployed ROADM network with a 120 Gbit/s polarization-multiplexed 64 QAM signal Peer-reviewed

Toshihiko Hirookaa, Keisuke Kasai, Yixin Wang, Masataka Nakazawa, Masaki Shiraiwa, Yoshinari Awaji, Naoya Wada

IEICE ELECTRONICS EXPRESS　12　(23)　20150884　2015/12

DOI： 10.1587/elex.12.20150884 　

ISSN： 1349-2543
Q-factor analysis of nonlinear impairments in ultrahigh-speed Nyquist pulse transmission Peer-reviewed

Toshihiko Hirooka, Masataka Nakazawa

OPTICS EXPRESS　23　(26)　33484-33492　2015/12

DOI： 10.1364/OE.23.033484 　

ISSN： 1094-4087
448 Gbit/s, 32 Gbaud 128 QAM coherent transmission over 150 km with a potential spectral efficiency of 10.7 bit/s/Hz Peer-reviewed

Keisuke Kasai, Yixin Wang, David Odeke Otuya, Masato Yoshida, Masataka Nakazawa

OPTICS EXPRESS　23　(22)　28423-28429　2015/11

DOI： 10.1364/OE.23.028423 　

ISSN： 1094-4087
80 Gbit/s, 256 QAM coherent transmission over 150 km with an injection-locked homodyne receiver Peer-reviewed

Keisuke Kasai, Yixin Wang, Shohei Beppu, Masato Yoshida, Masataka Nakazawa

OPTICS EXPRESS　23　(22)　29174-29183　2015/11

DOI： 10.1364/OE.23.029174 　

ISSN： 1094-4087
2.56 Tbit/s/ch (640 Gbaud) polarization-multiplexed DQPSK non-coherent Nyquist pulse transmission over 525 km Peer-reviewed

Koudai Harako, Daiki Seya, Daiki Suzuki, Toshihiko Hirooka, Masataka Nakazawa

OPTICS EXPRESS　23　(24)　30801-30806　2015/11

DOI： 10.1364/OE.23.030801 　

ISSN： 1094-4087
High-speed, high spectrally efficient 64 QAM orthogonal TDM coherent Nyquist pulse transmission Invited Peer-reviewed

Keisuke Kasai, David Odeke Otuya, Koudai Harako, Toshihiko Hirooka, Masataka Nakazawa

2015 IEEE Summer Topicals Meeting Series, SUM 2015　76-77　2015/09/09
Publisher: Institute of Electrical and Electronics Engineers Inc.
DOI： 10.1109/PHOSST.2015.7248201 　
1024 QAM, 7-core (60 Gbit/s x 7) fiber transmission over 55 km with an aggregate potential spectral efficiency of 109 bit/s/Hz Peer-reviewed

Masato Yoshida, Shohei Beppu, Keisuke Kasai, Toshihiko Hirooka, Masataka Nakazawa

OPTICS EXPRESS　23　(16)　20760-20766　2015/08

DOI： 10.1364/OE.23.020760 　

ISSN： 1094-4087
Ultrafast Nyquist OTDM demultiplexing using optical Nyquist pulse sampling in an all-optical nonlinear switch Peer-reviewed

Toshihiko Hirooka, Daiki Seya, Koudai Harako, Daiki Suzuki, Masataka Nakazawa

OPTICS EXPRESS　23　(16)　20858-20866　2015/08

DOI： 10.1364/OE.23.020858 　

ISSN： 1094-4087
Distributed mode-coupling measurements in MCF and FMF using a synchronous multi-channel OTDR Invited Peer-reviewed

M. Nakazawa

International Symposium on Ultrafast Photonic Technologies/Extremely Advanced Transmission Technology (ISUPT/EXAT 2015)　T1.2　2015/07
HCN frequency-stabilized 10 GHz mode-locked fiber laser Peer-reviewed

K. Yoshida, K. Kasai, M. Yoshida, M. Nakazawa

International Symposium on Ultrafast Photonic Technologies/Extremely Advanced Transmission Technology (ISUPT/EXAT 2015)　P-34　2015/07
2.56 Tbit/s/ch polarization-multiplexed DQPSK non-coherent Nyquist pulse transmission over 525 km Peer-reviewed

D. Suzuki, D. Seya, K. Harako, T. Hirooka, M. Nakazawa

International Symposium on Ultrafast Photonic Technologies/Extremely Advanced Transmission Technology (ISUPT/EXAT 2015)　2015　P-35-1　2015/07
Publisher: Organizing Committee of Tohoku-Section Joint Convention of Institutes of Electrical and Information Engineers, Japan
DOI： 10.11528/tsjc.2015.0_1 　
Multi-core Fibers and Systems for Space-division Multiplexing Invited Peer-reviewed

T. Hirooka, M. Yoshida, K. Kasai, M. Nakazawa

Photonics North 2015　7.60　2015/05
Real-time 10 Gbit/s-16 QAM quantum stream cipher transmission over 320 km with FPGA-based transmitter and receiver Peer-reviewed

M. Yoshida, T. Hirooka, K. Kasai, M. Nakazawa

Optical Fiber Communication Conference (OFC2015)　W4F.4　2015/03
2048 QAM (66 Gbit/s) single-carrier coherent optical transmission over 150 km with a potential SE of 15.3 bit/s/Hz Peer-reviewed

Shohei Beppu, Keisuke Kasai, Masato Yoshida, Masataka Nakazawa

OPTICS EXPRESS　23　(4)　4960-4969　2015/02

DOI： 10.1364/OE.23.004960 　

ISSN： 1094-4087
10 GHz, 0.95 ps coherent optical pulse source based on 1.55 μm HCN frequency-stabilized mode-locked fiber laser

Tohoku-Section Joint Convention Record of Institutes of Electrical and Information Engineers, Japan　2015　2-2　2015
Publisher: Organizing Committee of Tohoku-Section Joint Convention of Institutes of Electrical and Information Engineers, Japan
DOI： 10.11528/tsjc.2015.0_2 　
An 11.6 W output, 6 kHz linewidth, single-polarization EDFA-MOPA system with a (C2H2)-C-13 frequency stabilized fiber laser Peer-reviewed

Akira Fujisaki, Shunichi Matsushita, Keisuke Kasai, Masato Yoshida, Toshihiko Hirooka, Masataka Nakazawa

OPTICS EXPRESS　23　(2)　1081-1087　2015/01

DOI： 10.1364/OE.23.001081 　

ISSN： 1094-4087
Ad-Hoc Photonic Network based on Movable and Deployable ICT Resource Unit to meet rapidly changing service demands Peer-reviewed

Toshikazu Sakano, Tetsuro Komukai, Atsushi Takahara, Toshihiko Hirooka, Masataka Nakazawa

2015 OPTICAL FIBER COMMUNICATIONS CONFERENCE AND EXHIBITION (OFC)　M2A.1　2015
Single-Channel 1.92 Tbit/s, 64 QAM Coherent Orthogonal TDM Transmission of 160 Gbaud Optical Nyquist Pulses with 10.6 bit/s/Hz Spectral Efficiency Peer-reviewed

David Odeke Otuya, Koudai Harako, Keisuke Kasai, Toshihiko Hirooka, Masataka Nakazawa

2015 OPTICAL FIBER COMMUNICATIONS CONFERENCE AND EXHIBITION (OFC)　M3G.2　2015
256 QAM (Polarization-multiplexed, 5 Gsymbol/s) Coherent Transmission with an Injection-locked Homodyne Detection Technique Peer-reviewed

Keisuke Kasai, Shohei Beppu, Yixin Wang, Masataka Nakazawa

2015 OPTICAL FIBER COMMUNICATIONS CONFERENCE AND EXHIBITION (OFC)　W1E.4　2015
Generation of 10 W, 100 fs, 10 GHz pulse train using high power EDFA-MOPA system with cascaded Raman pumping Peer-reviewed

Akira Fujisaki, Masato Yoshida, Toshihiko Hirooka, Masataka Nakazawa

2015 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO)　STh1L.7　2015

ISSN： 2160-9020
Ultrafast spectrally-efficient TDM multiplexing/demultiplexing schemes using orthogonality in coherent optical nyquist pulses Invited Peer-reviewed

Masataka Nakazawa

Signal Processing in Photonic Communications, SPPCom 2015　262　2015
Publisher: Optical Society of America (OSA)
DOI： 10.1364/SPPCOM.2015.SpM3E.1 　
QAM Quantum Noise Stream Cipher Transmission with Extremely High Security Invited Peer-reviewed

Masataka Nakazawa

ECOC 2015 41ST EUROPEAN CONFERENCE ON OPTICAL COMMUNICATION　Th.2.5.1　2015

DOI： 10.1109/ECOC.2015.7341891 　
Real-time Adaptive 4-64 QAM, 20-60 Gbit/s Quantum Noise Stream Cipher Transmission over 320 km with FPGA-based Transmitter and Receiver Peer-reviewed

Masato Yoshida, Toshihiko Hirooka, Keisuke Kasai, Masataka Nakazawa

ECOC 2015 41ST EUROPEAN CONFERENCE ON OPTICAL COMMUNICATION　P.5.13　2015

DOI： 10.1109/ECOC.2015.7341787 　
QAM Quantum Noise Stream Cipher Using Digital Coherent Optical Transmission Invited Peer-reviewed

M. Yoshida, T. Hirooka, K. Kasai, M. Nakazawa

2015 49TH ASILOMAR CONFERENCE ON SIGNALS, SYSTEMS AND COMPUTERS　1007-1011　2015

DOI： 10.1109/ACSSC.2015.7421290 　
Measurement of mode coupling distribution along a few-mode fiber using a synchronous multi-channel OTDR Peer-reviewed

Masataka Nakazawa, Masato Yoshida, Toshihiko Hirooka

OPTICS EXPRESS　22　(25)　31299-31309　2014/12

DOI： 10.1364/OE.22.031299 　

ISSN： 1094-4087
High-performance TDM demultiplexing of coherent Nyquist pulses using time-domain orthogonality Peer-reviewed

Koudai Harako, David Odeke Otuya, Keisuke Kasai, Toshihiko Hirooka, Masataka Nakazawa

OPTICS EXPRESS　22　(24)　29456-29464　2014/12

DOI： 10.1364/OE.22.029456 　

ISSN： 1094-4087
120 Gbit/s injection-locked homodyne coherent transmission of polarization-multiplexed 64 QAM signals over 150 km Peer-reviewed

Yixin Wang, Keisuke Kasai, Masato Yoshida, Masataka Nakazawa

OPTICS EXPRESS　22　(25)　31310-31316　2014/12

DOI： 10.1364/OE.22.031310 　

ISSN： 1094-4087
Evolution of EDFA from single-core to multi-core and related recent progress in optical communication Invited Peer-reviewed

Masataka Nakazawa

Optical Review　21　(6)　862-874　2014/11/27
Publisher: SpringerOpen
DOI： 10.1007/s10043-014-0139-1 　

ISSN： 1349-9432 1340-6000
Real-time adaptive 4-64 QAM coherent optical transmission over 320 km with FPGA-based transmitter and receiver Peer-reviewed

Masato Yoshida, Toshihiko Hirooka, Keisuke Kasai, Masataka Nakazawa

European Conference on Optical Communication, ECOC　Th2.5.2　2014/11/20
Publisher: Institute of Electrical and Electronics Engineers Inc.
DOI： 10.1109/ECOC.2014.6963904 　
Evolution of EDFA from Single-Core to Multi-Core and Related Recent Progress in Optical Communication

Masataka Nakazawa

OPTICAL REVIEW　21　(6)　862-874　2014/11

DOI： 10.1007/s10043-014-0139-1 　

ISSN： 1340-6000

eISSN： 1349-9432
Exabit Optical Communication Infrastructure Using 3M Scheme Invited Peer-reviewed

M. Nakazawa

Asia Communications and Photonics Conference (ACP2014)　Plenary Talk　2014/11
140 Gbit/s, 128 QAM LD-based Coherent Transmission over 150 km with an Injection-locked Homodyne Detection Technique Peer-reviewed

Y. Wang, S. Beppu, K. Kasai, M. Yoshida, M. Nakazawa

Asia Communications and Photonics Conference (ACP2014)　ATh1E.3　2014/11
A Single-channel 40 Gbit/s Digital Coherent QAM Quantum Stream Cipher Transmission over 480 km Peer-reviewed

M. Nakazawa, M. Yoshida, T. Hirooka

Asia Communications and Photonics Conference (ACP2014)　ATh4E.1　2014/11
Single-channel 1.92 Tbit/s, Pol-Mux-64 QAM coherent Nyquist pulse transmission over 150 km with a spectral efficiency of 7.5 bit/s/Hz Peer-reviewed

David Odeke Otuya, Keisuke Kasai, Masato Yoshida, Toshihiko Hirooka, Masataka Nakazawa

OPTICS EXPRESS　22　(20)　23776-23785　2014/10

DOI： 10.1364/OE.22.023776 　

ISSN： 1094-4087
The Nyquist laser Peer-reviewed

Masataka Nakazawa, Masato Yoshida, Toshihiko Hirooka

OPTICA　1　(1)　15-22　2014/07

DOI： 10.1364/OPTICA.1.000015 　

ISSN： 2334-2536
Plug-and-Play Optical Interconnection Using Digital Coherent Technology for Resilient Network Based on Movable and Deployable ICT Resource Unit Peer-reviewed

Tetsuro Komukai, Hirokazu Kubota, Toshikazu Sakano, Toshihiko Hirooka, Masataka Nakazawa

IEICE TRANSACTIONS ON COMMUNICATIONS　E97B　(7)　1334-1341　2014/07

DOI： 10.1587/transcom.E97.B.1334 　

ISSN： 1745-1345
Exabit optical communication explored using 3M scheme Invited Peer-reviewed

Masataka Nakazawa

JAPANESE JOURNAL OF APPLIED PHYSICS　53　(8)　08MA01-1-08MA01-9　2014/07

DOI： 10.7567/JJAP.53.08MA01 　

ISSN： 0021-4922

eISSN： 1347-4065
Adaptive 4 similar to 64 QAM real-time coherent optical transmission over 320 km with FPGA-based transmitter and receiver Peer-reviewed

Masato Yoshida, Toshihiko Hirooka, Keisuke Kasai, Masataka Nakazawa

OPTICS EXPRESS　22　(13)　16520-16527　2014/06

DOI： 10.1364/OE.22.016520 　

ISSN： 1094-4087
QAM quantum stream cipher using digital coherent optical transmission Peer-reviewed

Masataka Nakazawa, Masato Yoshida, Toshihiko Hirooka, Keisuke Kasai

OPTICS EXPRESS　22　(4)　4098-4107　2014/02

DOI： 10.1364/OE.22.004098 　

ISSN： 1094-4087
A 380 fs, 40 GHz mode-locked erbium fiber laser with an MQW nonlinear PM/AM modulator using the pockels effect and the QCSE

Masataka Nakazawa, Masato Yoshida, Ken Tsuzuki

Optics InfoBase Conference Papers　2014
Publisher: Optical Society of America (OSA)
DOI： 10.1364/cleo_si.2014.stu1n.6 　

ISSN： 2162-2701
A 160 mW output, 5 kHz linewidth frequency-stabilized erbium silica fiber laser with a short cavity configuration

Keisuke Kasai, Akira Fujisaki, Masato Yoshida, Toshihiko Hirooka, Masataka Nakazawa, Shin Masuda

Optics InfoBase Conference Papers　2014
Publisher: Optical Society of America (OSA)
DOI： 10.1364/cleo_si.2014.sw1n.4 　

ISSN： 2162-2701
2048 QAM coherent optical transmission over 150 km

Tohoku-Section Joint Convention Record of Institutes of Electrical and Information Engineers, Japan　2014　(0)　13-13　2014
Publisher: Organizing Committee of Tohoku-Section Joint Convention of Institutes of Electrical and Information Engineers, Japan
DOI： 10.11528/tsjc.2014.0_13 　
1.92 Tbit/s, 64 QAM Coherent Nyquist Pulse Transmission over 150 km with a Spectral Efficiency of 7.5 bit/s/Hz Peer-reviewed

David Odeke Otuya, Keisuke Kasai, Toshihiko Hirooka, Masato Yoshida, Masataka Nakazawa

2014 OPTICAL FIBER COMMUNICATIONS CONFERENCE AND EXHIBITION (OFC)　W1A.4　2014
2048 QAM (66 Gbit/s) Single-Carrier Coherent Optical Transmission over 150 km with a Potential SE of 15.3 bit/s/Hz Peer-reviewed

Shohei Beppu, Keisuke Kasai, Masato Yoshida, Masataka Nakazawa

2014 OPTICAL FIBER COMMUNICATIONS CONFERENCE AND EXHIBITION (OFC)　W1A.6　2014
100 Gbit/s DP-QPSK Transmission over a 32 km Legacy Multi-Mode GI Fiber Using a Real-Time Digital Coherent Transceiver Peer-reviewed

Toshihiko Hirooka, Masataka Nakazawa, Tetsuro Komukai, Toshikazu Sakano

2014 OPTICAL FIBER COMMUNICATIONS CONFERENCE AND EXHIBITION (OFC)　W2A.1　2014
Measurement of Mode Coupling Distribution Along a Few-Mode Fiber Using a Synchronous Multi-Channel OTDR Peer-reviewed

Masataka Nakazawa, Masato Yoshida, Toshihiko Hirooka

2014 OPTICAL FIBER COMMUNICATIONS CONFERENCE AND EXHIBITION (OFC)　W3D.7　2014
All-Optical High-Performance Demultiplexing Using Optical Nyquist Pulse Sampling Peer-reviewed

Daiki Seya, Koudai Harako, Toshihiko Hirooka, Masataka Nakazawa

2014 OPTICAL FIBER COMMUNICATIONS CONFERENCE AND EXHIBITION (OFC)　W4F.2　2014
A 380 fs, 40 GHz Mode-Locked Erbium Fiber Laser with an MQW Nonlinear PM/AM Modulator Using the Pockels Effect and the QCSE Peer-reviewed

Masataka Nakazawa, Masato Yoshida, Ken Tsuzuki

2014 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO)　STu1N.6　2014

ISSN： 2160-9020
A 160 mW Output, 5 kHz Linewidth Frequency-Stabilized Erbium Silica Fiber Laser with a Short Cavity Configuration Peer-reviewed

Keisuke Kasai, Akira Fujisaki, Masato Yoshida, Toshihiko Hirooka, Masataka Nakazawa, Shin Masuda

2014 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO)　SW1N.4　2014

ISSN： 2160-9020
Ultrahigh Spectral Efficiency Systems - Pushing the Limits of Multi-level Modulation, Multi-core Fiber, and Multi-mode Control Invited Peer-reviewed

Masataka Nakazawa

2014 OPTOELECTRONICS AND COMMUNICATIONS CONFERENCE AND AUSTRALIAN CONFERENCE ON OPTICAL FIBRE TECHNOLOGY (OECC/ACOFT 2014)　597-599　2014
Q Margin Comparison of RZ and Nyquist Optical Pulses in Ultrahigh-Speed TDM Transmission Peer-reviewed

Toshihiko Hirooka, Lei Chen, Masataka Nakazawa

2014 OPTOELECTRONICS AND COMMUNICATIONS CONFERENCE AND AUSTRALIAN CONFERENCE ON OPTICAL FIBRE TECHNOLOGY (OECC/ACOFT 2014)　79-80　2014
A 6 kHz Linewidth, Injection-Locked LD Using a Master Erbium Fiber Laser Peer-reviewed

Yixin Wang, Keisuke Kasai, Masato Yoshida, Masataka Nakazawa

2014 OPTOELECTRONICS AND COMMUNICATIONS CONFERENCE AND AUSTRALIAN CONFERENCE ON OPTICAL FIBRE TECHNOLOGY (OECC/ACOFT 2014)　417-418　2014
100 Gbit/s real-time digital coherent transmission over a 32 km legacy multi-mode graded-index fiber Peer-reviewed

Toshihiko Hirooka, Masataka Nakazawa, Tetsuro Komukai, Toshikazu Sakano

IEICE ELECTRONICS EXPRESS　11　(15)　20140563　2014

DOI： 10.1587/elex.11.20140563 　

ISSN： 1349-2543
60 Gbit/s, 64 QAM LD-based injection-locked coherent heterodyne transmission over 160 km with a spectral efficiency of 9 bit/s/Hz Peer-reviewed

Yixin Wang, Keisuke Kasai, Masato Yoshida, Masataka Nakazawa

IEICE ELECTRONICS EXPRESS　11　(18)　20140601　2014

DOI： 10.1587/elex.11.20140641 　

ISSN： 1349-2543
OH-Free, Low Loss Single-Mode Fibre Fabricated by Slurry Casting / Rod-in-Tube Method Peer-reviewed

Tamotsu Yajima, Jun Yamamoto, Yusuke Kinoshita, Futoshi Ishii, Toshihiko Hirooka, Masato Yoshida, Masataka Nakazawa

2014 EUROPEAN CONFERENCE ON OPTICAL COMMUNICATION (ECOC)　Th2.4.4　2014

DOI： 10.1109/ECOC.2014.6963829 　
Novel Ultrafast TDM Demultiplexing Scheme Using Orthogonality in Coherent Nyquist Pulses Peer-reviewed

Koudai Harako, David Odeke Otuya, Keisuke Kasai, Toshihiko Hirooka, Masataka Nakazawa

2014 EUROPEAN CONFERENCE ON OPTICAL COMMUNICATION (ECOC)　Tu4.6.5　2014

DOI： 10.1109/ECOC.2014.6963952 　
A Single-Channel 960 Gbit/s 64 QAM Orthogonal TDM Transmission with a Spectral Efficiency of 10.0 bit/s/Hz Using Coherent Nyquist Pulses Peer-reviewed

David Odeke Otuya, Koudai Harako, Keisuke Kasai, Toshihiko Hirooka, Masataka Nakazawa

2014 EUROPEAN CONFERENCE ON OPTICAL COMMUNICATION (ECOC)　We.2.3.4　2014

DOI： 10.1109/ECOC.2014.6964004 　
Measurement of Mode Coupling Distribution Along a Few-Mode Fiber Using a Synchronous Multi-Channel OTDR Peer-reviewed

Masataka Nakazawa, Masato Yoshida, Toshihiko Hirooka

2014 OPTICAL FIBER COMMUNICATIONS CONFERENCE AND EXHIBITION (OFC)　22　(25)　31299-31309　2014

DOI： 10.1364/OE.22.031299 　
OH-Free, Low Loss Single-Mode Fibre Fabricated by Slurry Casting / Rod-in-Tube Method Peer-reviewed

Tamotsu Yajima, Jun Yamamoto, Yusuke Kinoshita, Futoshi Ishii, Toshihiko Hirooka, Masato Yoshida, Masataka Nakazawa

2014 EUROPEAN CONFERENCE ON OPTICAL COMMUNICATION (ECOC)　13　(1)　20151005　2014

DOI： 10.1587/elex.12.20151005 　
Detailed comparison between mode couplings along multi-core fibers and structural irregularities using a synchronous multi-channel OTDR system with a high dynamic range Peer-reviewed

Masato Yoshida, Toshihiko Hirooka, Masataka Nakazawa, Katsunori Imamura, Ryuichi Sugizaki, Takeshi Yagi

Optics Express　21　(24)　29157-29164　2013/12/02
Publisher: Optical Society of American (OSA)
DOI： 10.1364/OE.21.029157 　

ISSN： 1094-4087
Low-loss photonic crystal fiber fabricated by a slurry casting method Peer-reviewed

Tamotsu Yajima, Jun Yamamoto, Futoshi Ishii, Toshihiko Hirooka, Masato Yoshida, Masataka Nakazawa

OPTICS EXPRESS　21　(25)　30500-30506　2013/12

DOI： 10.1364/OE.21.030500 　

ISSN： 1094-4087
120 Gbit/s, polarization-multiplexed 10 Gsymbol/s, 64 QAM coherent transmission over 150 km using an optical voltage controlled oscillator Peer-reviewed

Yixin Wang, Keisuke Kasai, Tatsunori Omiya, Masataka Nakazawa

OPTICS EXPRESS　21　(23)　28290-28296　2013/11

DOI： 10.1364/OE.21.028290 　

ISSN： 1094-4087
A single-channel 1.28 Tbit/s-58 km transmission in the 1.1 mu m band with wideband GVD and slope compensation Peer-reviewed

Kengo Koizumi, Masato Yoshida, Toshihiko Hirooka, Masataka Nakazawa

OPTICS EXPRESS　21　(23)　29055-29064　2013/11

DOI： 10.1364/OE.21.029055 　

ISSN： 1094-4087
Nondestructive measurement of mode-coupling along a multi-core fiber using a synchronous multi-channel OTDR Invited Peer-reviewed

M. Nakazawa, M. Yoshida, T. Hirooka

International Symposium on Extremely Advanced Transmission Technology (EXAT 2013)　pp. 60-pp.63　2013/11
Investigation of the Influence of Fusion Splice on Crosstalk Properties of Multicore Fiber Peer-reviewed

K. Imamura, R. Sugizaki, T. Yagi, M. Yoshida, M. Nakazawa

IWCS 2013　P-1　2013/11
Disaster-resilient networks and optical communication technologies Invited Peer-reviewed

M. Nakazawa

Journal of the Institute of Electronics, Information and Communication Engineers　96　(10)　748-751　2013/10
Exa-bit optical communication exploring by 3M scheme Invited Peer-reviewed

M. Nakazawa

18th Microoptics Conference (MOC’13)　Plenary Talk　2013/10
640 Gbaud (1.28 Tbit/s/ch) optical Nyquist pulse transmission over 525 km with substantial PMD tolerance Peer-reviewed

Koudai Harako, Daiki Seya, Toshihiko Hirooka, Masataka Nakazawa

Optics Express　21　(18)　21062-21075　2013/09/09
Publisher: Optical Society of American (OSA)
DOI： 10.1364/OE.21.021062 　

ISSN： 1094-4087
A single-channel 1.92 Tbit/s, 64 QAM coherent optical pulse transmission over 150 km using frequency-domain equalization Peer-reviewed

David Odeke Otuya, Keisuke Kasai, Masato Yoshida, Toshihiko Hirooka, Masataka Nakazawa

OPTICS EXPRESS　21　(19)　22808-22816　2013/09

DOI： 10.1364/OE.21.022808 　

ISSN： 1094-4087
Disaster-Resilient Networking: A New Vision Based on Movable and Deployable Resource Units

Toshikazu Sakano, Zubair Md Fadlullah, Thuan Ngo, Hiroki Nishiyama, Masataka Nakazawa, Fumiyuki Adachi, Nei Kato, Atsushi Takahara, Tomoaki Kumagai, Hiromichi Kasahara, Shigeki Kurihara

IEEE NETWORK　27　(4)　40-46　2013/07

DOI： 10.1109/MNET.2013.6574664 　

ISSN： 0890-8044

eISSN： 1558-156X
1 Tbit/s 256 QAM-OFDM transmission over 560 km with 14.3 bit/s/Hz spectral efficiency Peer-reviewed

T. Omiya, M. Yoshida, M. Nakazawa

OECC2013　MR1-2　2013/07
Resilient Photonic Network Architecture with Plug & play Optical Interconnection Technology Peer-reviewed

T. Sakano, H. Kubota, T. Komukai, T. Hirooka, M. Nakazawa

OECC2013　TuQ3-5　2013/07
A Single-Channel 1.92 Tbit/s, 64 QAM Coherent Pulse OTDM Transmission over 150 km Peer-reviewed

D. O. Otuya, K. Kasai, T. Hirooka, M. Yoshida, M. Nakazawa

OECC2013　WR2-2　2013/07
Marked Reduction of Depolarization-Induced Crosstalk in Ultrahigh-Speed Pol-MUX Transmission with an Optical Nyquist Pulse Peer-reviewed

K. Harako, T. Hirooka, M. Nakazawa

OECC2013　WR4-5　2013/07
Orthogonal TDM Using Optical Nyquist Pulses Invited Peer-reviewed

T. Hirooka, M. Nakazawa

Signal Processing in Photonic Communications (SPPCom 2013)　SPM1D.3　2013/07
Extremely Higher-Order Modulation Formats Peer-reviewed

Masataka Nakazawa, Toshihiko Hirooka, Masato Yoshida, Keisuke Kasai

Optical Fiber Telecommunications VIB: Systems and Networks: Sixth Edition　297-336　2013/05/13
Publisher: Elsevier Inc.
DOI： 10.1016/B978-0-12-396960-6.00007-9 　
400 Gbit/s 256 QAM-OFDM Transmission over 720 km with a 14 bit/s/Hz Spectral Efficiency Using an Improved FDE Technique Peer-reviewed

T. Omiya, M. Yoshida, M. Nakazawa

Optical Fiber Communication Conference (OFC2013)　OTh4E.1　2013/03
Multicore EDFA for DWDM transmission in full c-band Peer-reviewed

Y. Tsuchida, K. Maeda, K. Watanabe, T. Ito, K. Fukuchi, M. Yoshida, Y. Mimura, R. Sugizaki, M. Nakazawa

Optical Fiber Communication Conference (OFC2013)　JW2A.16　2013/03
400 Gbit/s 256 QAM-OFDM transmission over 720 km with a 14 bit/s/Hz spectral efficiency by using high-resolution FDE Peer-reviewed

Tatsunori Omiya, Masato Yoshida, Masataka Nakazawa

OPTICS EXPRESS　21　(3)　2632-2641　2013/02

DOI： 10.1364/OE.21.002632 　

ISSN： 1094-4087
160 Gbit/s-300 km single-channel transmission in the 1.1 mu m band with a precise GVD and slope compensation Peer-reviewed

Kengo Koizumi, Masato Yoshida, Toshihiko Hirooka, Masataka Nakazawa

OPTICS EXPRESS　21　(4)　4303-4310　2013/02

DOI： 10.1364/OE.21.004303 　

ISSN： 1094-4087
EXA-BIT OPTICAL COMMUNICATION EXPLORING BY 3M SCHEME

Masataka Nakazawa

2013 18TH MICROOPTICS CONFERENCE (MOC)　2013
A 1.5 µm Passively Mode-locked Fiber Soliton Laser with a Graphene-doped PVA Saturable Absorber

Tohoku-Section Joint Convention Record of Institutes of Electrical and Information Engineers, Japan　2013　(0)　23-23　2013
Publisher: Organizing Committee of Tohoku-Section Joint Convention of Institutes of Electrical and Information Engineers, Japan
DOI： 10.11528/tsjc.2013.0_23 　
Second-order PMD-induced crosstalk between polarization-multiplexed signals and its impact on ultrashort optical pulse transmission Peer-reviewed

Toshihiko Hirooka, Koudai Harako, Pengyu Guan, Masataka Nakazawa

Journal of Lightwave Technology　31　(5)　809-814　2013

DOI： 10.1109/JLT.2012.2236884 　

ISSN： 0733-8724
An LD-Based Ultra-Low Phase Noise OPLL Circuit Using an Optical Voltage Controlled Oscillator Peer-reviewed

Keisuke Kasai, Yixin Wang, Masataka Nakazawa

2013 OPTICAL FIBER COMMUNICATION CONFERENCE AND EXPOSITION AND THE NATIONAL FIBER OPTIC ENGINEERS CONFERENCE (OFC/NFOEC)　OW3D.2　2013
A Single-Channel, 1.6 Tbit/s 32 QAM Coherent Pulse Transmission Over 150 km With RZ-CW Conversion and FDE Techniques Peer-reviewed

David Odeke Otuya, Keisuke Kasai, Toshihiko Hirooka, Masato Yoshida, Masataka Nakazawa, Tokutaka Hara, Satoshi Oikawa

2013 OPTICAL FIBER COMMUNICATION CONFERENCE AND EXPOSITION AND THE NATIONAL FIBER OPTIC ENGINEERS CONFERENCE (OFC/NFOEC)　OTh4E.4　2013
Large PMD Tolerant 1.28 Tbit/s/ch Transmission over 525 km with 640 Gbaud Optical Nyquist Pulses Peer-reviewed

Koudai Harako, Peng Ruan, Toshihiko Hirooka, Masataka Nakazawa

2013 OPTICAL FIBER COMMUNICATION CONFERENCE AND EXPOSITION AND THE NATIONAL FIBER OPTIC ENGINEERS CONFERENCE (OFC/NFOEC)　JW2A.38　2013
Generation of 9 W, 4 kHz linewidth (C2H2)-C-13 frequency-stabilized fiber laser output with core pumped erbium-doped amplifier Peer-reviewed

Akira Fujisaki, Keisuke Kasai, Masato Yoshida, Toshihiko Hirooka, and Masataka Nakazawa

2013 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO)　CW3M.1　2013

ISSN： 2160-9020
Measurement of Structural Irregularity Dependence on Mode Coupling along Multi-Core Fiber Using Multi-Channel OTDR System Peer-reviewed

Masato Yoshida, Toshihiko Hirooka, Masataka Nakazawa, Katsunori Imamura, Ryuichi Sugizaki, Takeshi Yagi

2013 IEEE PHOTONICS SOCIETY SUMMER TOPICAL MEETING SERIES　84-+　2013

DOI： 10.1109/PHOSST.2013.6614464 　
Disaster-resilient networking: A new vision based on movable and deployable resource units Peer-reviewed

Toshikazu Sakano, Zubair Fadlullah, Thuan Ngo, Hiroki Nishiyama, Masataka Nakazawa, Fumiyuki Adachi, Nei Kato, Atsushi Takahara, Tomoaki Kumagai, Hiromichi Kasahara, Shigeki Kurihara

IEEE Network　27　(4)　40-46　2013

DOI： 10.1109/MNET.2013.6574664 　

ISSN： 0890-8044
Dynamic optical transport connection with a 100 Gbit/s digital coherent optical transponder for disaster-resilient networking Peer-reviewed

Toshihiko Hirooka, Masataka Nakazawa, Hirokazu Kubota, Tetsuro Komukai, Toshikazu Sakano

2013 IEEE Region 10 Humanitarian Technology Conference, R10-HTC 2013　261-263　2013

DOI： 10.1109/R10-HTC.2013.6669052 　
120 Gbit/s, 64 QAM coherent transmission employing an optical voltage controlled oscillator Peer-reviewed

Yixin Wang, Keisuke Kasai, Tatsunori Omiya, Masataka Nakazawa

IET Conference Publications　2013　(622)　110-112　2013

DOI： 10.1049/cp.2013.1309 　
Single-channel 1.28 Tbit/s transmission over 58 km in the 1.1 μm band with wideband GVD and dispersion slope compensation Peer-reviewed

Kengo Koizumi, Toshihiko Hirooka, Masato Yoshida, Masataka Nakazawa

IET Conference Publications　2013　(622)　615-617　2013

DOI： 10.1049/cp.2013.1478 　
512 QAM transmission over 240 km using frequency-domain equalization in a digital coherent receiver Peer-reviewed

Yuki Koizumi, Kazushi Toyoda, Tatsunori Omiya, Masato Yoshida, Toshihiko Hirooka, Masataka Nakazawa

OPTICS EXPRESS　20　(21)　23383-23389　2012/10

DOI： 10.1364/OE.20.023383 　

ISSN： 1094-4087
A 31 mW, 280 fs passively mode-locked fiber soliton laser using a high heat-resistant SWNT/P3HT saturable absorber coated with siloxane Peer-reviewed

Takato Ono, Yuichiro Hori, Masato Yoshida, Toshihiko Hirooka, Masataka Nakazawa, Junji Mata, Jun Tsukamoto

OPTICS EXPRESS　20　(21)　23659-23665　2012/10

DOI： 10.1364/OE.20.023659 　

ISSN： 1094-4087
Marked performance improvement of 256 QAM transmission using a digital back-propagation method Peer-reviewed

Kazushi Toyoda, Yuki Koizumi, Tatsunori Omiya, Masato Yoshida, Toshihiko Hirooka, Masataka Nakazawa

OPTICS EXPRESS　20　(18)　19815-19821　2012/08

DOI： 10.1364/OE.20.019815 　

ISSN： 1094-4087
Linear and nonlinear propagation of optical Nyquist pulses in fibers Peer-reviewed

Toshihiko Hirooka, Masataka Nakazawa

OPTICS EXPRESS　20　(18)　19836-19849　2012/08

DOI： 10.1364/OE.20.019836 　

ISSN： 1094-4087
Highly dispersion-tolerant 160 Gbaud optical Nyquist pulse TDM transmission over 525 km Peer-reviewed

Toshihiko Hirooka, Peng Ruan, Pengyu Guan, Masataka Nakazawa

OPTICS EXPRESS　20　(14)　15001-15007　2012/07

DOI： 10.1364/OE.20.015001 　

ISSN： 1094-4087
1024 QAM (60 Gbit/s) single-carrier coherent optical transmission over 150 km Peer-reviewed

Yuki Koizumi, Kazushi Toyoda, Masato Yoshida, Masataka Nakazawa

OPTICS EXPRESS　20　(11)　12508-12514　2012/05

DOI： 10.1364/OE.20.012508 　

ISSN： 1094-4087
Nondestructive measurement of mode couplings along a multi-core fiber using a synchronous multi-channel OTDR Peer-reviewed

Masataka Nakazawa, Masato Yoshida, Toshihiko Hirooka

OPTICS EXPRESS　20　(11)　12530-12540　2012/05

DOI： 10.1364/OE.20.012530 　

ISSN： 1094-4087
Single-Carrier 800-Gb/s 32 RZ/QAM Coherent Transmission Over 225 km Employing a Novel RZ-CW Conversion Technique Peer-reviewed

Keisuke Kasai, David Odeke Otuya, Masato Yoshida, Toshihiko Hirooka, Masataka Nakazawa

IEEE PHOTONICS TECHNOLOGY LETTERS　24　(5)　416-418　2012/03

DOI： 10.1109/LPT.2011.2180373 　

ISSN： 1041-1135

eISSN： 1941-0174
64 QAM real-time coherent transmission using FPGA-based receiver Peer-reviewed

M. Yoshida, T. Omiya, K. Kasai, M. Nakazawa

IEICE Trans. Comm.　J95-B　(3)　405-413　2012/03

ISSN： 1344-4697
Extremely Advanced Transmission with 3M Technologies (Multi-level Modulation, Multi-core & Multi-mode) Invited Peer-reviewed

M. Nakazawa

Optical Fiber Communication Conference (OFC2012)　OTu1D.1　2012/03
Measurement of Mode Couplings along a Multi-Core Fiber Using a Multi-Channel OTDR Peer-reviewed

M. Nakazawa, M. Yoshida, T. Hirooka

Optical Fiber Communication Conference (OFC2012)　OTh3I.3　2012/03
Bandwidth and distance dependences of depolarization-induced crosstalk in polarization-multiplexed transmission Peer-reviewed

T. Hirooka, K. Harako, P. Guan, M. Nakazawa

Optical Fiber Communication Conference (OFC2012)　JW2A.44　2012/03
400 Gbit/s Frequency-Division-Multiplexed and Polarization-Multiplexed 256 QAM-OFDM Transmission over 400 km with a Spectral Efficiency of 14 bit/s/Hz Peer-reviewed

T. Omiya, K. Toyoda, M. Yoshida, M. Nakazawa

Optical Fiber Communication Conference (OFC2012)　OM2A.7　2012/03
1.6 Tbit/s, Single-carrier 32 RZ/QAM Coherent Transmission Over 150 km Utilizing an RZ-CW Conversion Scheme

Otuya David Odeke

Tohoku-Section Joint Convention Record of Institutes of Electrical and Information Engineers, Japan　2012　12-12　2012
Publisher: Organizing Committee of Tohoku-Section Joint Convention of Institutes of Electrical and Information Engineers, Japan
DOI： 10.11528/tsjc.2012.0_12 　
Ultrahigh-speed "orthogonal" TDM transmission with an optical Nyquist pulse train Peer-reviewed

Masataka Nakazawa, Toshihiko Hirooka, Peng Ruan, Pengyu Guan

OPTICS EXPRESS　20　(2)　1129-1140　2012/01

DOI： 10.1364/OE.20.001129 　

ISSN： 1094-4087
Ultrafast Coherent Optical Transmission Invited Peer-reviewed

Masataka Nakazawa, Toshihiko Hirooka, Masato Yoshida, Keisuke Kasai

IEEE JOURNAL OF SELECTED TOPICS IN QUANTUM ELECTRONICS　18　(1)　363-376　2012/01

DOI： 10.1109/JSTQE.2011.2125781 　

ISSN： 1077-260X

eISSN： 1558-4542
Low Loss Photonic Crystal Fiber Fabricated by Slurry Casting Method Invited Peer-reviewed

Tamotsu Yajima, Jun Yamamoto, Futoshi Ishii, Toshihiko Hirooka, Masato Yoshida, Masataka Nakazawa

2012 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO)　CTh3G.1　2012

ISSN： 2160-9020
Preparation for ultrahigh-capacity SDM transmission Invited Peer-reviewed

Masataka Nakazawa

2012 IEEE Photonics Society Summer Topical Meeting Series, PSST 2012　171-172　2012

DOI： 10.1109/PHOSST.2012.6280718 　
A Cesium optical atomic clock with high optical frequency stability Peer-reviewed

Kazunari Tokuhira, Fumitaka Suzuki, Masato Yoshida, Masataka Nakazawa

IEICE ELECTRONICS EXPRESS　9　(18)　1496-1503　2012

DOI： 10.1587/elex.9.1496 　

ISSN： 1349-2543
Low Loss Photonic Crystal Fiber Fabricated by Slurry Casting Method Peer-reviewed

Tamotsu Yajima, Jun Yamamoto, Futoshi Ishii, Toshihiko Hirooka, Masato Yoshida, Masataka Nakazawa

2012 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO)　21　(25)　30500-30506　2012

DOI： 10.1364/OE.21.030500 　

ISSN： 2160-9020
10 GHz, 1.1 ps optical pulse generation from a regeneratively mode-locked Yb fiber laser in the 1.1 mu m band Peer-reviewed

Kengo Koizumi, Masato Yoshida, Toshihiko Hirooka, Masataka Nakazawa

OPTICS EXPRESS　19　(25)　25426-25432　2011/12

DOI： 10.1364/OE.19.025426 　

ISSN： 1094-4087
2.56 Tbit/s/ch polarization-multiplexed DQPSK transmission over 300 km using time-domain optical Fourier transformation Peer-reviewed

Pengyu Guan, Toshiyuki Hirano, Koudai Harako, Yutaro Tomiyama, Toshihiko Hirooka, Masataka Nakazawa

OPTICS EXPRESS　19　(26)　567-573　2011/12

DOI： 10.1364/OE.19.00B567 　

ISSN： 1094-4087
PMD-Induced Crosstalk in Ultrahigh-Speed Polarization-Multiplexed Optical Transmission in the Presence of PDL Peer-reviewed

Toshihiko Hirooka, Toshiyuki Hirano, Yutaro Tomiyama, Pengyu Guan, Masataka Nakazawa

JOURNAL OF LIGHTWAVE TECHNOLOGY　29　(19)　2963-2970　2011/10

DOI： 10.1109/JLT.2011.2163617 　

ISSN： 0733-8724
Comparison between polarization-multiplexed DPSK and single-polarization DQPSK in 640 Gbaud, 1.28 Tbit/s-500 km single-channel transmission Invited Peer-reviewed

Yutaro Tomiyama, Koudai Harako, Pengyu Guan, Toshihiko Hirooka, Masataka Nakazawa

OPTICAL FIBER TECHNOLOGY　17　(5)　439-444　2011/10

DOI： 10.1016/j.yofte.2011.07.007 　

ISSN： 1068-5200
“Multi” is everywhere Invited Peer-reviewed

M. Nakazawa

Chitose International Forum on Photonics Science & Technology　2011/10
CNT-based mode-locked lasers Invited Peer-reviewed

M. Nakazawa

17th Microoptics Conference (MOC’11)　E-2　2011/10
Absolutely optical-frequency-stabilized cesium optical atomic clock Peer-reviewed

M. Yoshida, F. Suzuki, T. Morisaki, M. Nakazawa

17th Microoptics Conference (MOC’11)　B-2　2011/10
Absolute frequency stabilization of a laser diode based on triple ring resonators to an C₂H₂ absorption line Peer-reviewed

K. Kasai, M. Nakazawa, H. Yamazaki

17th Microoptics Conference (MOC’11)　G-4　2011/10
10 GHz, 1.1 ps pulse generation from a harmonically and regeneratively mode-locked Yb fiber laser at 1.1 μm Peer-reviewed

K. Koizumi, M. Yoshida, T. Hirooka, M. Nakazawa

17th Microoptics Conference (MOC’11)　H-22　2011/10
1070 nm passively mode-locked ytterbium-doped fiber solition laser with SWNT/PMMA saturable absorber Peer-reviewed

Y. Hori, Z. Zhang, M. Nakazawa

17th Microoptics Conference (MOC’11)　H-18　2011/10
Introduction

NAKAZAWA Masataka

IEEJ Transactions on Sensors and Micromachines　131　(9)　596-597　2011/09/01
Publisher: The Institute of Electrical Engineers of Japan
DOI： 10.1541/ieejjournal.131.596 　

ISSN： 1340-5551

More details Close

This article has no abstract.
Polarization-multiplexed, 10 Gsymbol/s, 64 QAM coherent transmission over 150 km with OPLL-based homodyne detection employing narrow linewidth LDs Peer-reviewed

Yixin Wang, Keisuke Kasai, Masataka Nakazawa

IEICE ELECTRONICS EXPRESS　8　(17)　1444-1449　2011/09

DOI： 10.1587/elex.8.1444 　

ISSN： 1349-2543
Ultra high capacity optical fiber transmission technologies Peer-reviewed

K. Fukuchi, M. Nakazawa

IEEJ Journal　131　(9)　611-613　2011/09
Publisher: The Institute of Electrical Engineers of Japan
DOI： 10.1541/ieejjournal.131.611 　

ISSN： 1340-5551

More details Close

This article has no abstract.
Novel RZ-CW Conversion Scheme for Ultra Multi-level, High-speed Coherent OTDM Transmission Peer-reviewed

M. Nakazawa, K. Kasai, M. Yoshida, T. Hirooka

European Conference on Optical Communication (ECOC2011)　We.10.P1.75　2011/09
1.5-mu m Frequency-Stabilized lambda/4-Shifted DFB LD Employing an External Fiber Ring Cavity With a Linewidth of 2.6 kHz and an RIN of-135 dB/Hz Peer-reviewed

Keisuke Kasai, Anne Mori, Masataka Nakazawa

IEEE PHOTONICS TECHNOLOGY LETTERS　23　(15)　1046-1048　2011/08

DOI： 10.1109/LPT.2011.2150211 　

ISSN： 1041-1135
“Multi” is everywhere Invited Peer-reviewed

M. Nakazawa

Korea-Japan Workshop on Beyond 100G　2011/06
Recent Progress on Ultra-high Speed and Multi Level Coherent Transmission Invited Peer-reviewed

T. Hirooka, K. Kasai, M. Nakazawa

Korea-Japan Workshop on Beyond 100G　2011/06
Science and technology challenges in XXIst century optical communications Invited Peer-reviewed

E. Desurvire, C. Kazmierski, F. Lelarge, X. Marcadet, Andre Scavennec, F. A. Kish, D. F. Welch, R. Nagarajan, C. H. Joyner, R. P. Schneider, S. W. Corzine, M. Kato, P. W. Evans, M. Ziari, A. G. Dentai, J. L. Pleumeekers, R. Muthiah, S. Bigo, M. Nakazawa, D. J. Richardson, F. Poletti, M. N. Petrovich, S. U. Alam, W. H. Loh, D. N. Payne

COMPTES RENDUS PHYSIQUE　12　(4)　387-416　2011/05

DOI： 10.1016/j.crhy.2011.04.009 　

ISSN： 1631-0705

eISSN： 1878-1535
256 QAM Digital Coherent Optical Transmission Using Raman Amplifiers Peer-reviewed

Masato Yoshida, Seiji Okamoto, Tatsunori Omiya, Keisuke Kasai, Masataka Nakazawa

IEICE TRANSACTIONS ON COMMUNICATIONS　E94B　(2)　417-424　2011/02

DOI： 10.1587/transcom.E94.B.417 　

ISSN： 0916-8516

eISSN： 1745-1345
Single-Channel 1.28 Tbit/s-525 km DQPSK Transmission Using Ultrafast Time-Domain Optical Fourier Transformation and Nonlinear Optical Loop Mirror Peer-reviewed

Pengyu Guan, Hans Christian Hansen Mulvad, Yutaro Tomiyama, Toshiyuki Hirano, Toshihiko Hirooka, Masataka Nakazawa

IEICE TRANSACTIONS ON COMMUNICATIONS　E94B　(2)　430-436　2011/02

DOI： 10.1587/transcom.E94.B.430 　

ISSN： 0916-8516

eISSN： 1745-1345
A 13C2H2 frequency-stabilized λ/4-shifted dfb laser diode with an external fiber ring cavity having a linewidth of 2.6 kHz and a RIN of-135 dB/Hz

Keisuke Kasai, Anne Mori, Masataka Nakazawa

Optics InfoBase Conference Papers　2011

ISSN： 2162-2701
A precise OPLL circuit employing narrow linewidth LDs and its application to coherent optical QAM transmission

Tohoku-Section Joint Convention Record of Institutes of Electrical and Information Engineers, Japan　2011　22-22　2011
Publisher: Organizing Committee of Tohoku-Section Joint Convention of Institutes of Electrical and Information Engineers, Japan
DOI： 10.11528/tsjc.2011.0_22 　
2.56 Tbit/s/ch Polarization-Multiplexed DQPSK Transmission over 300 km Using Time-Domain Optical Fourier Transformation Peer-reviewed

Pengyu Guan, Toshiyuki Hirano, Koudai Harako, Yutaro Tomiyama, Toshihiko Hirooka, Masataka Nakazawa

2011 37TH EUROPEAN CONFERENCE AND EXHIBITION ON OPTICAL COMMUNICATIONS (ECOC 2011)　2011
Investigation and comparison of digital backward propagation schemes for OFDM and single-carrier fiber-optic transmission systems Peer-reviewed

Dong Yang, Shiva Kumar, M. Nakazawa

OPTICAL FIBER TECHNOLOGY　17　(1)　84-90　2011/01

DOI： 10.1016/j.yofte.2010.11.001 　

ISSN： 1068-5200
Real-time FPGA-based Coherent Optical Receiver for 1 Gsymbol/s, 64 QAM Transmission Peer-reviewed

Masato Yoshida, Tatsunori Omiya, Keisuke Kasai, Masataka Nakazawa

2011 OPTICAL FIBER COMMUNICATION CONFERENCE AND EXPOSITION (OFC/NFOEC) AND THE NATIONAL FIBER OPTIC ENGINEERS CONFERENCE　OTuN3　2011
New PMD-Induced Crosstalk in the Presence of PDL in a Polarization-Multiplexed Ultrahigh-Speed Transmission Peer-reviewed

Toshihiko Hirooka, Toshiyuki Hirano, Pengyu Guan, Masataka Nakazawa

2011 OPTICAL FIBER COMMUNICATION CONFERENCE AND EXPOSITION (OFC/NFOEC) AND THE NATIONAL FIBER OPTIC ENGINEERS CONFERENCE　JThA44　2011
Ultrafast and High-Spectral-Density Optical Communications Systems Invited Peer-reviewed

Masataka Nakazawa

2011 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO)　CThGG3　2011

ISSN： 2160-9020
A (C2H2)-C-13 Frequency-Stabilized lambda/4-shifted DFB Laser Diode with an External Fiber Ring Cavity Having a Linewidth of 2.6 kHz and a RIN of-135 dB/Hz Peer-reviewed

Keisuke Kasai, Anne Mori, Masataka Nakazawa

2011 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO)　CTuV4　2011

ISSN： 2160-9020
A 10 GHz 2.5 ps Regeneratively Mode-Locked Yb Fiber Laser in the 1.1 mu m Band Peer-reviewed

Kengo Koizumi, Masato Yoshida, Toshihiko Hirooka, Masataka Nakazawa

2011 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO)　CMBB3　2011

ISSN： 2160-9020
Novel RZ-CW Conversion Scheme for Ultra Multi-Level, High-Speed Coherent OTDM Transmission Peer-reviewed

Masataka Nakazawa, Keisuke Kasai, Masato Yoshida, Toshihiko Hirooka

2011 37TH EUROPEAN CONFERENCE AND EXHIBITION ON OPTICAL COMMUNICATIONS (ECOC 2011)　19　(26)　B574-B580　2011
High Time-Resolution 640-Gb/s Clock Recovery Using Time-Domain Optical Fourier Transformation and Narrowband Optical Filter Peer-reviewed

Pengyu Guan, Hans Christian Hansen Mulvad, Keisuke Kasai, Toshihiko Hirooka, Masataka Nakazawa

IEEE PHOTONICS TECHNOLOGY LETTERS　22　(23)　1735-1737　2010/12

DOI： 10.1109/LPT.2010.2083644 　

ISSN： 1041-1135
Recent progress on ultra-high speed and multi level coherent transmission Invited Peer-reviewed

T. Hirooka, M. Nakazawa

Photonics 2010　M2B3　2010/12
Optical frequency-tunable Cs atomic clock with a 9.19GHz mode-hop-free fiber laser Peer-reviewed

Takahito Morisaki, Masato Yoshida, Masataka Nakazawa

IEICE ELECTRONICS EXPRESS　7　(21)　1652-1658　2010/11

DOI： 10.1587/elex.7.1652 　

ISSN： 1349-2543
Real time monitoring of a fiber fuse using an optical time-domain reflectometer Peer-reviewed

Kazi S. Abedin, Masataka Nakazawa

OPTICS EXPRESS　18　(20)　21315-21321　2010/09

DOI： 10.1364/OE.18.021315 　

ISSN： 1094-4087
Giant leaps in optical communication technologies towards 2030 and beyond Invited Peer-reviewed

M. Nakazawa

European Conference on Optical Communication (ECOC 2010)　Plenary Talk　2010/09
60Gbit/s 64 QAM-OFDM coherent optical transmission with a 5.3GHz bandwidth Peer-reviewed

Tatsunori Omiya, Seiji Okamoto, Keisuke Kasai, Masato Yoshida, Masataka Nakazawa

IEICE ELECTRONICS EXPRESS　7　(15)　1163-1168　2010/08

DOI： 10.1587/elex.7.1163 　

ISSN： 1349-2543
640-Gb/s/Channel Single-Polarization DPSK Transmission Over 525 km With Ultrafast Time-Domain Optical Fourier Transformation Peer-reviewed

Toshiyuki Hirano, Pengyu Guan, Toshihiko Hirooka, Masataka Nakazawa

IEEE PHOTONICS TECHNOLOGY LETTERS　22　(14)　1042-1044　2010/07

DOI： 10.1109/LPT.2010.2049483 　

ISSN： 1041-1135

eISSN： 1941-0174
Hardware paradigm shifts in the optical communication infrastructure with three “M technologies Invited Peer-reviewed

M. Nakazawa

Opto Electronics and Communications Conference (OECC 2010)　Plenary Talk　2010/07
Advances in information communication technology lased on lasers Invited Peer-reviewed

M. Nakazawa

Journal of Applied Physics (Oyo Butsuri)　79　(6)　508-516　2010/06
131 fs, 33 MHz all-fiber soliton laser at 1.07 mu m with a film-type SWNT saturable absorber coated on polyimide Peer-reviewed

Fumio Shohda, Yuichiro Hori, Masataka Nakazawa, Junji Mata, Jun Tsukamoto

OPTICS EXPRESS　18　(11)　11223-11229　2010/05

DOI： 10.1364/OE.18.011223 　

ISSN： 1094-4087
Single-Channel 400-Gb/s OTDM-32 RZ/QAM Coherent Transmission Over 225 km Using an Optical Phase-Locked Loop Technique Peer-reviewed

Keisuke Kasai, Tatsunori Omiya, Pengyu Guan, Masato Yoshida, Toshihiko Hirooka, Masataka Nakazawa

IEEE PHOTONICS TECHNOLOGY LETTERS　22　(8)　562-564　2010/04

DOI： 10.1109/LPT.2010.2042708 　

ISSN： 1041-1135
A 113 fs fiber laser operating at 1.56 mu m using a cascadable film-type saturable absorber with P3HT-incorporated single-wall carbon nanotubes coated on polyamide Peer-reviewed

Fumio Shohda, Masataka Nakazawa, Junji Mata, Jun Tsukamoto

OPTICS EXPRESS　18　(9)　9712-9721　2010/04

DOI： 10.1364/OE.18.009712 　

ISSN： 1094-4087
Device requirements for next generation optical transmission technology Invited Peer-reviewed

M. Nakazawa

European Conference on Integrated Optics (ECIO2010)　FrC1　2010/04
A 10-GHz Optoelectronic Oscillator at 1.1 mu m Using a Single-Mode VCSEL and a Photonic Crystal Fiber Peer-reviewed

Kengo Koizumi, Masato Yoshida, Masataka Nakazawa

IEEE PHOTONICS TECHNOLOGY LETTERS　22　(5)　293-295　2010/03

DOI： 10.1109/LPT.2009.2038892 　

ISSN： 1041-1135
256-QAM (64 Gb/s) Coherent Optical Transmission Over 160 km With an Optical Bandwidth of 5.4 GHz Peer-reviewed

Masataka Nakazawa, Seiji Okamoto, Tatsunori Omiya, Keisuke Kasai, Masato Yoshida

IEEE PHOTONICS TECHNOLOGY LETTERS　22　(3)　185-187　2010/02

DOI： 10.1109/LPT.2009.2037238 　

ISSN： 1041-1135
Recent progress on OTDM terabit/s transmission and their future

Toshihiko Hirooka, M. Nakazawa, M. Yoshida, K. Kasai, P. Guan, T. Hirano

2010 Conference on Optical Fiber Communication, Collocated National Fiber Optic Engineers Conference, OFC/NFOEC 2010　2010
An 88 fs Fiber Soliton Laser at 1.56 mu m using a Quantum Well Saturable Absorber with an Ultrafast Intersubband Transition Peer-reviewed

Fumio Shohda, Masataka Nakazawa, Ryoichi Akimoto, Hiroshi Ishikawa

2010 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO) AND QUANTUM ELECTRONICS AND LASER SCIENCE CONFERENCE (QELS)　17　(25)　22499-22504　2010

DOI： 10.1364/OE.17.022499 　
A 10 GHz Opto-electronic Oscillator at 1.1 mu m Using a Gain-Switched InGaAs VCSEL and a Photonic Crystal Fiber Peer-reviewed

Kengo Koizumi, Masato Yoshida, Masataka Nakazawa

2010 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO) AND QUANTUM ELECTRONICS AND LASER SCIENCE CONFERENCE (QELS)　22　(5)　293-295　2010

DOI： 10.1109/LPT.2009.2038892 　
Recent progress on ultrafast/ultrashort/frequency-stabilized erbium-doped fiber lasers and their applications Invited Peer-reviewed

Masataka Nakazawa

Frontiers of Optoelectronics in China　3　(1)　38-44　2010

DOI： 10.1007/s12200-009-0085-x 　

ISSN： 1674-4128 1674-4594
256 QAM (64 Gbit/s) Coherent Optical Transmission over 160 km with an Optical Bandwidth of 5.4 GHz Peer-reviewed

Masataka Nakazawa, Seiji Okamoto, Tatsunori Omiya, Keisuke Kasai, Masato Yoshida

2010 CONFERENCE ON OPTICAL FIBER COMMUNICATION OFC COLLOCATED NATIONAL FIBER OPTIC ENGINEERS CONFERENCE OFC-NFOEC　OMJ5　2010
140 Gbit/s Coherent Optical Transmission over 150 km with a 10 Gsymbol/s Polarization-Multiplexed 128 QAM Signal Peer-reviewed

Seiji Okamoto, Tatsunori Omiya, Keisuke Kasai, Masato Yoshida, Masataka Nakazawa

2010 CONFERENCE ON OPTICAL FIBER COMMUNICATION OFC COLLOCATED NATIONAL FIBER OPTIC ENGINEERS CONFERENCE OFC-NFOEC　OThD5　2010
Single-Channel 400 Gbit/s, OTDM-32 RZ/QAM Coherent Transmission Over 225 km Using an Optical Phase-Locked Loop Technique Peer-reviewed

Keisuke Kasai, Tatsunori Omiya, Pengyu Guan, Masato Yoshida, Toshihiko Hirooka, Masataka Nakazawa

2010 CONFERENCE ON OPTICAL FIBER COMMUNICATION OFC COLLOCATED NATIONAL FIBER OPTIC ENGINEERS CONFERENCE OFC-NFOEC　OThD6　2010
640 Gbit/s Single-Polarization DPSK Transmission over 525 km with Time-Domain Optical Fourier Transformation in a Round-Trip Configuration Peer-reviewed

Toshiyuki Hirano, Pengyu Guan, Toshihiko Hirooka, Masataka Nakazawa

2010 CONFERENCE ON OPTICAL FIBER COMMUNICATION OFC COLLOCATED NATIONAL FIBER OPTIC ENGINEERS CONFERENCE OFC-NFOEC　OThD7　2010
10 Gbit/s Photonic Crystal Fiber Transmissions with 1.1 mu m Directly-Modulated Single-Mode VCSEL Peer-reviewed

Kengo Koizumi, Masato Yoshida, Toshihiko Hirooka, Masataka Nakazawa

2010 CONFERENCE ON OPTICAL FIBER COMMUNICATION OFC COLLOCATED NATIONAL FIBER OPTIC ENGINEERS CONFERENCE OFC-NFOEC　OWK3　2010
A 10 GHz Opto-electronic Oscillator at 1.1 mu m Using a Gain-Switched InGaAs VCSEL and a Photonic Crystal Fiber Peer-reviewed

Kengo Koizumi, Masato Yoshida, Masataka Nakazawa

2010 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO) AND QUANTUM ELECTRONICS AND LASER SCIENCE CONFERENCE (QELS)　CMA7　2010
Optical Frequency-Tunable Cs Atomic Clock with a Mode-Hop-Free Fiber Laser Peer-reviewed

Takahito Morisaki, Masato Yoshida, Masataka Nakazawa

2010 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO) AND QUANTUM ELECTRONICS AND LASER SCIENCE CONFERENCE (QELS)　CMN2　2010
A C(2)H(2) Frequency-Stabilized Laser Diode with a Linewidth of 4 kHz and Its Application to an Optical Phase-Locked Loop Peer-reviewed

Keisuke Kasai, Masataka Nakazawa

2010 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO) AND QUANTUM ELECTRONICS AND LASER SCIENCE CONFERENCE (QELS)　CTuKK7　2010
A Film-type Saturable Absorber with P3HT-incorporated Single-wall Carbon Nanotubes Coated on Polyamide and its Application to a Femtosecond Fiber Laser Peer-reviewed

Fumio Shohda, Masataka Nakazawa, Junji Mata, Jun Tsukamoto

2010 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO) AND QUANTUM ELECTRONICS AND LASER SCIENCE CONFERENCE (QELS)　JTuD52　2010
An 88 fs Fiber Soliton Laser at 1.56 mu m using a Quantum Well Saturable Absorber with an Ultrafast Intersubband Transition Peer-reviewed

Fumio Shohda, Masataka Nakazawa, Ryoichi Akimoto, Hiroshi Ishikawa

2010 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO) AND QUANTUM ELECTRONICS AND LASER SCIENCE CONFERENCE (QELS)　JTuD60　2010
High-Resolution 640 Gbit/s Clock Recovery using Time-Domain Optical Fourier Transformation and Narrowband Optical Filter Peer-reviewed

H. C. Hansen Mulvad, P. Guan, K. Kasai, T. Hirooka, M. Nakazawa

2010 36TH EUROPEAN CONFERENCE AND EXHIBITION ON OPTICAL COMMUNICATION (ECOC), VOLS 1 AND 2　Mo.1.A.6　2010

DOI： 10.1109/ECOC.2010.5621124 　
1.28 Tbit/s/channel Single-polarization DQPSK Transmission over 525 km Using Ultrafast Time-domain Optical Fourier Transformation Peer-reviewed

Pengyu Guan, Hans Christian Hansen Mulvad, Yutaro Tomiyama, Toshiyuki Hirano, Toshihiko Hirooka, Masataka Nakazawa

2010 36TH EUROPEAN CONFERENCE AND EXHIBITION ON OPTICAL COMMUNICATION (ECOC), VOLS 1 AND 2　We.6.C.3　2010

DOI： 10.1109/ECOC.2010.5621133 　
512 QAM (54 Gbit/s) Coherent Optical Transmission over 150 km with an Optical Bandwidth of 4.1 GHz Peer-reviewed

Seiji Okamoto, Kazushi Toyoda, Tatsunori Omiya, Keisuke Kasai, Masato Yoshida, Masataka Nakazawa

2010 36TH EUROPEAN CONFERENCE AND EXHIBITION ON OPTICAL COMMUNICATION (ECOC), VOLS 1 AND 2　PD2.3　2010

DOI： 10.1109/ECOC.2010.5621378 　
High-Resolution 640 Gbit/s Clock Recovery using Time-Domain Optical Fourier Transformation and Narrowband Optical Filter Peer-reviewed

H. C. Hansen Mulvad, P. Guan, K. Kasai, T. Hirooka, M. Nakazawa

2010 36TH EUROPEAN CONFERENCE AND EXHIBITION ON OPTICAL COMMUNICATION (ECOC), VOLS 1 AND 2　22　(23)　1735-1737　2010

DOI： 10.1109/LPT.2010.2083644 　
Low-Penalty 5 x 320 Gb/s/Single-Channel WDM DPSK Transmission Over 525 km Using Time-Domain Optical Fourier Transformation Peer-reviewed

Pengyu Guan, Masatada Okazaki, Toshiyuki Hirano, Toshihiko Hirooka, Masataka Nakazawa

IEEE PHOTONICS TECHNOLOGY LETTERS　21　(21)　1579-1581　2009/11

DOI： 10.1109/LPT.2009.2029074 　

ISSN： 1041-1135
10-GHz 11.5-ps Pulse Generation From a Single-Mode Gain-Switched InGaAs VCSEL at 1.1 mu m Peer-reviewed

Kengo Koizumi, Masato Yoshida, Masataka Nakazawa

IEEE PHOTONICS TECHNOLOGY LETTERS　21　(22)　1704-1706　2009/11

DOI： 10.1109/LPT.2009.2031920 　

ISSN： 1041-1135
10Gbit/s photonic crystal fiber transmissions with 1.1 mu m directly-modulated single-mode VCSEL Peer-reviewed

Kengo Koizumi, Masato Yoshida, Toshihiko Hirooka, Masataka Nakazawa

IEICE ELECTRONICS EXPRESS　6　(22)　1615-1620　2009/11

DOI： 10.1587/elex.6.1615 　

ISSN： 1349-2543
All-Optical Demultiplexing of 640-Gb/s OTDM-DPSK Signal Using a Semiconductor SMZ Switch Peer-reviewed

Toshihiko Hirooka, Masatada Okazaki, Toshiyuki Hirano, Pengyu Guan, Masataka Nakazawa, Shigeru Nakamura

IEEE PHOTONICS TECHNOLOGY LETTERS　21　(20)　1574-1576　2009/10

DOI： 10.1109/LPT.2009.2029555 　

ISSN： 1041-1135

eISSN： 1941-0174
Measurements of spectral broadening and Doppler shift of backreflections from a fiber fuse using heterodyne detection Peer-reviewed

Kazi S. Abedin, Tetsuya Miyazaki, Masataka Nakazawa

OPTICS LETTERS　34　(20)　3157-3159　2009/10

DOI： 10.1364/OL.34.003157 　

ISSN： 0146-9592
20 years of EDFA and future prospects Invited Peer-reviewed

M. Nakazawa

IEICE Transactions on Electronics　J92-C　(8)　339-359　2009/08
Publisher: The Institute of Electronics, Information and Communication Engineers
ISSN： 1345-2827
FM-eliminated C2H2 frequency-stabilized laser diode with an RIN of-135 dB/Hz and a linewidth of 4 kHz Peer-reviewed

Keisuke Kasai, Masataka Nakazawa

OPTICS LETTERS　34　(14)　2225-2227　2009/07

DOI： 10.1364/OL.34.002225 　

ISSN： 0146-9592
Recent progress on ultrafast/ultrashort/frequency-stabilized erbium-doped fiber lasers and their applications Invited Peer-reviewed

M. Nakazawa

International Conference on Materials for Advanced Technologies (ICMAT 2009)　P-S1.3-4　2009/06
Backreflected radiation due to a propagating fiber fuse Peer-reviewed

Kazi S. Abedin, Masataka Nakazawa, Tetsuya Miyazaki

OPTICS EXPRESS　17　(8)　6525-6531　2009/04

DOI： 10.1364/OE.17.006525 　

ISSN： 1094-4087
Environmentally stable, simple passively mode-locked fiber ring laser using a four-port circulator Peer-reviewed

Shin Masuda, Shoji Niki, Masataka Nakazawa

OPTICS EXPRESS　17　(8)　6613-6622　2009/04

DOI： 10.1364/OE.17.006613 　

ISSN： 1094-4087
Ultra-multilevel coherent QAM optical transmission technology Peer-reviewed

M. Nakazawa

The Review of Laser Engineering　37　(3)　101-106　2009/03
147 fs, 51 MHz soliton fiber laser at 1.56 mu m with a fiber-connector-type SWNT/P3HT saturable absorber Invited Peer-reviewed

Fumio Shohda, Takafumi Shirato, Masataka Nakazawa, Junji Mata, Jun Tsukamoto

2009 CONFERENCE ON LASERS AND ELECTRO-OPTICS AND QUANTUM ELECTRONICS AND LASER SCIENCE CONFERENCE (CLEO/QELS 2009), VOLS 1-5　16　(25)　542-+　2009

DOI： 10.1364/OE.16.020943 　
A passively mode-locked femtosecond soliton fiber laser at 1.5 mu m with a CNT-doped polycarbonate saturable absorber Invited Peer-reviewed

Fumio Shohda, Takafumi Shirato, Masataka Nakazawa, Kyoji Komatsu, Toshikuni Kaino

2009 CONFERENCE ON LASERS AND ELECTRO-OPTICS AND QUANTUM ELECTRONICS AND LASER SCIENCE CONFERENCE (CLEO/QELS 2009), VOLS 1-5　16　(26)　538-+　2009

DOI： 10.1364/OE.16.021191 　
Optical Quadrature Amplitude Modulation (QAM) with Coherent Detection up to 128 States Peer-reviewed

Masataka Nakazawa

OFC: 2009 CONFERENCE ON OPTICAL FIBER COMMUNICATION, VOLS 1-5　1445-1447　2009
A passively mode-locked femtosecond soliton fiber laser at 1.5 mu m with a CNT-doped polycarbonate saturable absorber Peer-reviewed

Fumio Shohda, Takafumi Shirato, Masataka Nakazawa, Kyoji Komatsu, Toshikuni Kaino

2009 CONFERENCE ON LASERS AND ELECTRO-OPTICS AND QUANTUM ELECTRONICS AND LASER SCIENCE CONFERENCE (CLEO/QELS 2009), VOLS 1-5　538-+　2009
147 fs, 51 MHz soliton fiber laser at 1.56 mu m with a fiber-connector-type SWNT/P3HT saturable absorber Peer-reviewed

Fumio Shohda, Takafumi Shirato, Masataka Nakazawa, Junji Mata, Jun Tsukamoto

2009 CONFERENCE ON LASERS AND ELECTRO-OPTICS AND QUANTUM ELECTRONICS AND LASER SCIENCE CONFERENCE (CLEO/QELS 2009), VOLS 1-5　542-+　2009
C(2)H(2) absolutely optical frequency-stabilized and 40 GHz repetition-rate-stabilized, regeneratively mode-locked picosecond erbium fiber laser at 1.53 mu m Peer-reviewed

Masataka Nakazawa, Masato Yoshida, Keisuke Kasai

2009 CONFERENCE ON LASERS AND ELECTRO-OPTICS AND QUANTUM ELECTRONICS AND LASER SCIENCE CONFERENCE (CLEO/QELS 2009), VOLS 1-5　771-772　2009
Delivery of an ultrastable Cs optical atomic clock using a JGN II optical test bed Peer-reviewed

Masato Yoshida, Ikuro Kashiwamura, Toshihiko Hirooka, Masataka Nakazawa

2009 CONFERENCE ON LASERS AND ELECTRO-OPTICS AND QUANTUM ELECTRONICS AND LASER SCIENCE CONFERENCE (CLEO/QELS 2009), VOLS 1-5　1557-1558　2009
Ultrafast Transmission Technology using Time-Domain Optical Fourier Transformation Technique Invited Peer-reviewed

Toshihiko Hirooka, Masataka Nakazawa

2009 DIGEST OF THE LEOS SUMMER TOPICAL MEETINGS　73-74　2009

DOI： 10.1109/LEOSST.2009.5226260 　
24 Gbit/s, 64 QAM-OFDM Coherent Transmission with a Bandwidth of 2.5 GHz Peer-reviewed

Tatsunori Omiya, Hiroki Goto, Keisuke Kasai, Masato Yoshida, Masataka Nakazawa

2009 35TH EUROPEAN CONFERENCE ON OPTICAL COMMUNICATION (ECOC)　1.3.2　2009
All-Optical Demultiplexing of 640 Gbit/s OTDM-DPSK Signal Using a Semiconductor SMZ Switch Peer-reviewed

Toshihiko Hirooka, Masatada Okazaki, Toshiyuki Hirano, Pengyu Guan, Masataka Nakazawa, Shigeru Nakamura

2009 35TH EUROPEAN CONFERENCE ON OPTICAL COMMUNICATION (ECOC)　4.3.2　2009
Low-penalty 5x320 Gbit/s (1.6 Tbit/s) WDM DPSK Transmission over 525 km Using Time-domain Optical Fourier Transformation Peer-reviewed

Pengyu Guan, Masatada Okazaki, Toshiyuki Hirano, Toshihiko Hirooka, Masataka Nakazawa

2009 35TH EUROPEAN CONFERENCE ON OPTICAL COMMUNICATION (ECOC)　6.4.4　2009
A passively mode-locked femtosecond soliton fiber laser at 1.5 mu m with a CNT-doped polycarbonate saturable absorber Peer-reviewed

Fumio Shohda, Takafumi Shirato, Masataka Nakazawa, Kyoji Komatsu, Toshikuni Kaino

OPTICS EXPRESS　16　(26)　21191-21198　2008/12

DOI： 10.1364/OE.16.021191 　

ISSN： 1094-4087
147 fs, 51 MHz soliton fiber laser at 1.56 mu m with a fiber-connector-type SWNT/P3HT saturable absorber Peer-reviewed

Fumio Shohda, Takafumi Shirato, Masataka Nakazawa, Junji Mata, Jun Tsukamoto

OPTICS EXPRESS　16　(25)　20943-20948　2008/12

ISSN： 1094-4087
All-Optical 40-GHz Time. Domain Fourier Transformation Using XPM With a Dark Parabolic Pulse Invited Peer-reviewed

Toshihiko Hirooka, Masataka Nakazawa

IEEE PHOTONICS TECHNOLOGY LETTERS　20　(21-24)　1869-1871　2008/11

DOI： 10.1109/LPT.2008.2004879 　

ISSN： 1041-1135
320-Gb/s Single-Polarization DPSK Transmission Over 525 km Using Time-Domain Optical Fourier Transformation Invited Peer-reviewed

Toshihiko Hirooka, Masatada Okazaki, Pengyu Guan, Masataka Nakazawa

IEEE PHOTONICS TECHNOLOGY LETTERS　20　(21-24)　1872-1874　2008/11

DOI： 10.1109/LPT.2008.2004880 　

ISSN： 1041-1135
C2H2 absolutely optical frequency-stabilized and 40 GHz repetition-rate-stabilized, regeneratively mode-locked picosecond erbium fiber laser at 1.53 mu m Invited Peer-reviewed

Masataka Nakazawa, Keisuke Kasai, Masato Yoshida

OPTICS LETTERS　33　(22)　2641-2643　2008/11

DOI： 10.1364/OL.33.002641 　

ISSN： 0146-9592
160-Gb/s 200-km Field Transmission Experiment With Large PMD Using a Time-Domain Optical Fourier Transformation Technique Invited Peer-reviewed

Masatada Okazaki, Pengyu Guan, Toshihiko Hirooka, Masataka Nakazawa, Tetsuya Miyazaki

IEEE PHOTONICS TECHNOLOGY LETTERS　20　(21-24)　2192-2194　2008/11

DOI： 10.1109/LPT.2008.2006407 　

ISSN： 1041-1135
Toward the Shannon limit optical communication Peer-reviewed

M. Nakazawa

OSA Annual Meeting, Fronters in Optics (FiO2008)　2008/10
New scheme for independently stabilizing the repetition rate and optical frequency of a laser using a regenerative mode-locking technique Invited Peer-reviewed

M. Nakazawa, M. Yoshida

OSA Annual Meeting, Fronters in Optics (FiO2008)　2008/10
Polarization and frequency division multiplexed 1Gsymbol/s, 64 QAM coherent optical transmission with 8.6bit/s/Hz spectral efficiency over 160km

Hiroki Goto, Masato Yoshida, Tatsunori Omiya, Keisuke Kasai, Masataka Nakazawa

IEICE ELECTRONICS EXPRESS　5　(18)　776-781　2008/09/25

DOI： 10.1587/elex.5.776 　

ISSN： 1349-2543
A lambda/4-Shifted Distributed-Feedback Laser Diode With a Fiber Ring Cavity Configuration Having an OSNR of 85 dB and a Linewidth of 7 kHz Invited Peer-reviewed

Ho Thi Quynhanh, Akihito Suzuki, Masato Yoshida, Toshihiko Hirooka, Masataka Nakazawa

IEEE PHOTONICS TECHNOLOGY LETTERS　20　(17-20)　1578-1580　2008/09

DOI： 10.1109/LPT.2008.928848 　

ISSN： 1041-1135
Polarization and frequency division multiplexed 1Gsymbol/s, 64 QAM coherent optical transmission with 8.6bit/s/Hz spectral efficiency over 160km Invited Peer-reviewed

Hiroki Goto, Masato Yoshida, Tatsunori Omiya, Keisuke Kasai, Masataka Nakazawa

IEICE ELECTRONICS EXPRESS　5　(18)　776-781　2008/09

DOI： 10.1587/elex.5.776 　

ISSN： 1349-2543
Optimized amplification of femtosecond optical pulses by dispersion management for octave-spanning optical frequency comb generation Invited Peer-reviewed

Yoshiaki Nakajima, Hajime Inaba, Feng-Lei Hong, Atsushi Onae, Kaoru Minoshima, Takao Kobayashi, Masataka Nakazawa, Hirokazu Matsumoto

OPTICS COMMUNICATIONS　281　(17)　4484-4487　2008/09

DOI： 10.1016/j.optcom.2008.04.062 　

ISSN： 0030-4018
Stimulated Brillouin Scattering in Ultrahigh-Speed In-Phase RZ and CS-RZ OTDM Transmission Invited Peer-reviewed

Toshihiko Hirooka, Kou Osawa, Masatada Okazaki, Masataka Nakazawa, Hitoshi Murai

IEEE PHOTONICS TECHNOLOGY LETTERS　20　(17-20)　1694-1696　2008/09

DOI： 10.1109/LPT.2008.2003407 　

ISSN： 1041-1135
A straight-line 160-Gb/s DPSK transmission over 1000 km with time-domain optical Fourier transformation Invited Peer-reviewed

Toshihiko Hirooka, Masatada Okazaki, Masataka Nakazawa

IEEE PHOTONICS TECHNOLOGY LETTERS　20　(13-16)　1094-1096　2008/07

DOI： 10.1109/LPT.2008.924303 　

ISSN： 1041-1135
Optical communication going ahead of wireless communication in terms of spectral efficiency Peer-reviewed

M. Nakazawa

Workshop on High Spectral Density Optical Communication for New Generation Network　2008/06
Scheme for independently stabilizing the repetition rate and optical frequency of a laser using a regenerative mode-locking technique Invited Peer-reviewed

Masataka Nakazawa, Masato Yoshida

OPTICS LETTERS　33　(10)　1059-1061　2008/05

DOI： 10.1364/OL.33.001059 　

ISSN： 0146-9592
Bright and dark 4 GHz parabolic pulse generation using a picosecond optical pulse train and an arrayed waveguide grating Invited Peer-reviewed

Toshihiko Hirooka, Masataka Nakazawa, Katsunari Okamoto

OPTICS LETTERS　33　(10)　1102-1104　2008/05

DOI： 10.1364/OL.33.001102 　

ISSN： 0146-9592
1.5 mm passively mode-locked femtosecond fiber laser with CNT-doped polymer saturable absorber Invited Peer-reviewed

F. Shohda, T. Shirato, M. Nakazawa, K. Komatsu, T. Kaino

International Laser, Light-Wave and Microwave Conference (ILLMC 2008)　2008/04
1.5 μm femtsecond fiber laser with CNT-doped polymer saturable absorber Invited Peer-reviewed

M. Nakazawa

The 8th International Mini-Symposium on Advanced Organic Photonics (ISAOP-8)　I-11　2008/02
Frequency Division Multiplexed 1 Gsymbol/s, 64 QAM Coherent Optical Transmission with a Spectral Efficiency of 8.6 bit/s/Hz

Masato Yoshida, Hiroki Goto, Tatsunori Omiya, Keisuke Kasai, Masataka Nakazawa

2008 34TH EUROPEAN CONFERENCE ON OPTICAL COMMUNICATION (ECOC)　2008
Polarization-multiplexed 1 Gsymbol/s,128 QAM (14 Gbit/s) coherent optical transmission over 160 km with a 1.4 GHz bandwidth

Tohoku-Section Joint Convention Record of Institutes of Electrical and Information Engineers, Japan　2008　(0)　45-45　2008
Publisher: Organizing Committee of Tohoku-Section Joint Convention of Institutes of Electrical and Information Engineers, Japan
DOI： 10.11528/tsjc.2008.0_45 　
1.3 GHz ultranarrow FBG optical filter with 20-dB side lobe suppression

Tohoku-Section Joint Convention Record of Institutes of Electrical and Information Engineers, Japan　2008　(0)　46-46　2008
Publisher: Organizing Committee of Tohoku-Section Joint Convention of Institutes of Electrical and Information Engineers, Japan
DOI： 10.11528/tsjc.2008.0_46 　
Challenges to FDM-QAM Coherent Transmission with Ultrahigh Spectral Efficiency Peer-reviewed

Masataka Nakazawa

2008 34TH EUROPEAN CONFERENCE ON OPTICAL COMMUNICATION (ECOC)　2008
Dispersion management of femtosecond pulse amplification for octave-spanning optical frequency comb generation Peer-reviewed

Nakajima Y, Inaba H, Hong F.-L, Onae A, Minoshima K, Kobayashi T, Nakazawa M, Matsumoto H

Advanced Solid-State Photonics, ASSP 2008　2008
The use of a Nyquist filter for reducing an optical signal bandwidth in a coherent QAM optical transmission Peer-reviewed

Keisuke Kasai, Jumpei Hongo, Hiroki Goto, Masato Yoshida, Masataka Nakazawa

IEICE ELECTRONICS EXPRESS　5　(1)　6-10　2008/01

DOI： 10.1587/elex.5.6 　

ISSN： 1349-2543
64 and 128 coherent QAM optical transmission over 150 km using frequency-stabilized laser and heterodyne PLL detection Peer-reviewed

Masato Yoshida, Hiroki Goto, Keisuke Kasai, Masataka Nakazawa

OPTICS EXPRESS　16　(2)　829-840　2008/01

DOI： 10.1364/OE.16.000829 　

ISSN： 1094-4087
40 GHz bright and dark parabolic pulse generation using a picosecond optical pulse source and a 64-channel AWG Peer-reviewed

Toshihiko Hirooka, Masataka Nakazawa, Katsunari Okamoto

2008 CONFERENCE ON OPTICAL FIBER COMMUNICATION/NATIONAL FIBER OPTIC ENGINEERS CONFERENCE, VOLS 1-8　2212-+　2008

DOI： 10.1109/OFC.2008.4528579 　
All-optical 40 GHz time-domain Fourier transformation using XPM with a dark parabolic pulse Peer-reviewed

Toshihiko Hirooka, Masataka Nakazawa

OFC/NFOEC 2008 - 2008 Conference on Optical Fiber Communication/National Fiber Optic Engineers Conference　OThG5　2008

DOI： 10.1109/OFC.2008.4528464 　
Polarization-multiplexed 1 Gsymbol/s, 128 QAM (14 Gbit/s) coherent optical transmission over 160 km using a 1.4 GHz Nyquist filter Peer-reviewed

Hiroki Goto, Keisuke Kasai, Masato Yoshida, Masataka Nakazawa

2008 CONFERENCE ON OPTICAL FIBER COMMUNICATION/NATIONAL FIBER OPTIC ENGINEERS CONFERENCE, VOLS 1-8　133-135　2008

DOI： 10.1109/OFC.2008.4528075 　
Novel modulation format and high spectral efficiency technology for coherent optical communication systems Peer-reviewed

Masataka Nakazawa

2008 DIGEST OF THE LEOS SUMMER TOPICAL MEETINGS　111-112　2008

DOI： 10.1109/LEOSST.2008.4590514 　

ISSN： 1099-4742
Frequency Division Multiplexed 1 Gsymbol/s, 64 QAM Coherent Optical Transmission with a Spectral Efficiency of 8.6 bit/s/Hz Peer-reviewed

Masato Yoshida, Hiroki Goto, Tatsunori Omiya, Keisuke Kasai, Masataka Nakazawa

2008 34TH EUROPEAN CONFERENCE ON OPTICAL COMMUNICATION (ECOC)　2008

DOI： 10.1109/ECOC.2008.4729160 　
Challenges to FDM-QAM coherent transmission with ultrahigh spectral efficiency Peer-reviewed

Masataka Nakazawa

2008 34TH EUROPEAN CONFERENCE ON OPTICAL COMMUNICATION (ECOC)　2008

DOI： 10.1109/ECOC.2008.4729190 　
320 Gbit/s Single-Polarization DPSK Transmission over 525 km Using Time-domain Optical Fourier Transformation Invited Peer-reviewed

Toshihiko Hirooka, Masatada Okazaki, Pengyu Guan, Masataka Nakazawa

2008 34TH EUROPEAN CONFERENCE ON OPTICAL COMMUNICATION (ECOC)　2008

DOI： 10.1109/ECOC.2008.4729323 　
160 Gbit/s-200 km Field Transmission Experiment Using a Time-Domain Optical Fourier Transformation Technique with a Large PMD Invited Peer-reviewed

Masatada Okazaki, Pengyu Guan, Toshihiko Hirooka, Masataka Nakazawa, Tetsuya Miyazaki

2008 34TH EUROPEAN CONFERENCE ON OPTICAL COMMUNICATION (ECOC)　2008

DOI： 10.1109/ECOC.2008.4729498 　
An ultrastable Cs optical atomic clock with a 9.1926-GHz regeneratively mode-locked fiber laser Peer-reviewed

T. Hirayama, M. Yakabe, M. Yoshida, M. Nakazawa, Y. Koga, K. Hagimoto

IEICE Trans. Electron. (in Japanese)　J90-C　(12)　977-987　2007/12
Advanced optical fiber device technology for ultrahigh-speed transmission (Plenary talk) Invited Peer-reviewed

M. Nakazawa

5th Workshop on Fibers and Optical Passive Components (WFOPC2007)　2007/12
10 GHz regeneratively mode-locked semiconductor optical amplifier fiber ring laser and its linewidth characteristics Peer-reviewed

Masato Yoshida, Atsushi Ono, Masataka Nakazawa

OPTICS LETTERS　32　(24)　3513-3515　2007/12

DOI： 10.1364/OL.32.003513 　

ISSN： 0146-9592

eISSN： 1539-4794
Optical fiber transmission of standard signals using optical combs Peer-reviewed

M. Nakazawa, T. Hirooka, M. Yoshida

The Review of Laser Engineering (in Japanese)　35　(10)　649-653　2007/10
Publisher: The Laser Society of Japan
DOI： 10.2184/lsj.35.649 　

ISSN： 0387-0200

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Recently, the delivery of frequency standards using optical combs through optical fiber networks has become an important subject. When we transmit optical combs through an optical fiber network, it is very important to investigate the distortion in the power spectrum of the longitudinal modes that occurs during the transmission. In this paper, we describe the spectrum deformation of the longitudinal mode that occurs during long-haul transmission through a dispersion-shifted fiber, when we use a 10 GHz mode-locked fiber laser with a linewidth as narrow as 1 kHz as the signal source. We found that the deformation of the longitudinal mode power spectrum occurs mainly at the tail of the spectrum, and the linewidth broadening increases in proportion to the transmission distance. The main reason for the linewidth broadening was the phase fluctuation of the optical fiber caused by temperature fluctuation.
160 Gbit/s-900 km DPSK transmission with time-domain optical Fourier transformation Peer-reviewed

T. Hirooka, M. Okazaki, K. Osawa, M. Nakazawa

European Conference on Optical Communication (ECOC2007)　1.3.3　2007/09
A λ/4-shifted distributed feedback semiconductor fiber ring laser with an OSNR of 85 dB and a linewidth of 7 kHz Peer-reviewed

A. Suzuki, H. T. Quynhanh, M. Yoshida, M. Nakazawa

European Conference on Optical Communication (ECOC2007)　1.4.2　2007/09
Observation of stimulated Brillouin scattering in ultrahigh-speed in-phase and carrier-suppressed RZ OTDM transmission Peer-reviewed

T. Hirooka, K. Osawa, M. Okazaki, M. Nakazawa, H. Murai

European Conference on Optical Communication (ECOC2007)　P085　2007/09
A 10-GHz optoelectronic oscillator at 850 nm using a single-mode VCSEL and a photonic crystal fiber Peer-reviewed

Hideaki Hasegawa, Yosuke Oikawa, Masataka Nakazawa

IEEE PHOTONICS TECHNOLOGY LETTERS　19　(17-20)　1451-1453　2007/09

DOI： 10.1109/LPT.2007.903950 　

ISSN： 1041-1135
An ultralow noise and narrow linewidth lambda/4-shifted DFB Er-doped fiber laser with a ring cavity configuration Peer-reviewed

Akihito Suzuki, Youhei Takahashi, Masato Yoshida, Masataka Nakazawa

IEEE PHOTONICS TECHNOLOGY LETTERS　19　(17-20)　1463-1465　2007/09

DOI： 10.1109/LPT.2007.902697 　

ISSN： 1041-1135
New frontiers in optical communication: ultrahigh-speed transmission and coherent transmission Invited Peer-reviewed

M. Nakazawa

The 3rd International Symposium on Ultrafast Photonic Technolgies　Invited paper, I-1　2007/08
Regeneratively mode-locked fiber laser with a repetition rate stability of 4.9X10(-15) using a hydrogen maser phase-locked loop Peer-reviewed

Masato Yoshida, Toru Hirayama, Masataka Nakazawa, Ken Hagimoto, Takeshi Ikegami

OPTICS LETTERS　32　(13)　1827-1829　2007/07

DOI： 10.1364/OL.32.001827 　

ISSN： 0146-9592
Advanced optical fiber and fiber device technologies for ultrahigh-speed optical transmission Invited Peer-reviewed

M. Nakazawa

Optoelectronics and Communications Conference (OECC2007)　Tutotiral, 11C2-1　2007/07
Ultrahigh-speed signal transmission / processing technologies Invited Peer-reviewed

T. Hirooka, M. Nakazawa

Optoelectronics and Communications Conference (OECC2007)　Invited paper, 10B2-1　2007/07
Low power-penalty 160 Gbit/s DPSK transmission over 600 km Peer-reviewed

K. Osawa, M. Okazaki, T. Hirooka, M. Nakazawa

Optoelectronics and Communications Conference (OECC2007)　10B2-2　2007/07
A ring-type polarization-maintaining λ/4-shifted distributed feedback fiber laser pumped by 0.98 μm laser diode Peer-reviewed

Q. A. Ho Thi, A. Suzuki, M. Nakazawa

Optoelectronics and Communications Conference (OECC2007)　12C2-2　2007/07
10 GHz regeneratively mode-locked SOA fiber ring laser and its linewidth characteristics Peer-reviewed

M. Yoshida, A. Ono, M. Nakazawa

Optoelectronics and Communications Conference (OECC2007)　13C4-2　2007/07
1 Gsymbol/s, 64 QAM coherent optical transmission with a spectral efficiency of 8 bit/s/Hz using a Nyquist filter Peer-reviewed

K. Kasai, J. Hongo, H. Goto, M. Yoshida, M. Nakazawa

Optoelectronics and Communications Conference (OECC2007)　Postdeadline paper PD1-1　2007/07
Mode-hop-free, optical frequency tunable 40-GHz mode-locked fiber laser Peer-reviewed

Masato Yoshida, Keisuke Kasai, Masataka Nakazawa

IEEE JOURNAL OF QUANTUM ELECTRONICS　43　(7-8)　704-708　2007/07

DOI： 10.1109/JQE.2007.901289 　

ISSN： 0018-9197

eISSN： 1558-1713
10-GHz 8.7-ps pulse generation from a single-mode gain-switched AlGaAsVCSEL at 850 nm Peer-reviewed

Masataka Nakazawa, Hideaki Hasegawa, Yosuke Oikawa

IEEE PHOTONICS TECHNOLOGY LETTERS　19　(13-16)　1251-1253　2007/07

DOI： 10.1109/LPT.2007.901742 　

ISSN： 1041-1135
1-Gsymbol/s 64-QAM coherent optical transmission over 150 km

Jumpei Hongo, Keisuke Kasai, Masato Yoshida, Masataka Nakazawa

IEEE PHOTONICS TECHNOLOGY LETTERS　19　(9-12)　638-640　2007/05

DOI： 10.1109/LPT.2007.894944 　

ISSN： 1041-1135

eISSN： 1941-0174
1-Gsymbol/s 64-QAM coherent optical transmission over 150 km Peer-reviewed

Jumpei Hongo, Keisuke Kasai, Masato Yoshida, Masataka Nakazawa

IEEE PHOTONICS TECHNOLOGY LETTERS　19　(9-12)　638-640　2007/05

DOI： 10.1109/LPT.2007.894944 　

ISSN： 1041-1135

eISSN： 1941-0174
Mode-locked laser-type optical atomic clock with an optically pumped Cs gas cell Peer-reviewed

Toru Hirayama, Masato Yoshida, Masataka Nakazawa, Ken Hagimoto, Takeshi Ikegami

OPTICS LETTERS　32　(10)　1241-1243　2007/05

DOI： 10.1364/OL.32.001241 　

ISSN： 0146-9592
A new Cs optical atomic clock using ultrastable fiber laser and optical comb delivery through optical network (Invited talk) Invited Peer-reviewed

M. Nakazawa

NMIJ-BIPM Joint Workshop　2007/05
An ultrastable Cs optical atomic clock with a regeneratively mode-locked fiber laser and an optically pumped Cs gas cell Peer-reviewed

T. Hirayama, M. Yoshida, M. Nakazawa, K. Hagimoto, T. Ikegami

Conference on Lasers and Elecro-Optics (CLEO 2007)　Postdeadline paper, CPDB11　2007/05
40 Gbit/s-2 km photonic crystal fibre transmission with 850 nm singlemode VCSEL Peer-reviewed

H. Hasegawa, Y. Oikawa, T. Hirooka, M. Nakazawa

ELECTRONICS LETTERS　43　(11)　642-644　2007/05

DOI： 10.1049/el:20070171 　

ISSN： 0013-5194
A CW, polarization-maintaining lambda/4-shifted DFB Er-doped fiber laser at 1.54 mu m Peer-reviewed

Akihito Suzuki, Youhei Takahashi, Masato Yoshida, Masataka Nakazawa

IEICE ELECTRONICS EXPRESS　4　(8)　251-257　2007/04

DOI： 10.1587/elex.4.251 　

ISSN： 1349-2543
Advanced fiber laser technology for microwave photonics (Plenary Talk) Invited Peer-reviewed

M. Nakazawa

Asia-Pacific Microwave Photonics Conference (AP-MWP 2007),　2007/04
Highly spectral-efficient QAM coherent transmission using an optical phase-locked loop over long distances Peer-reviewed

K. Kasai, J. Hongou, M. Yoshida, M. Nakazawa

Asia-Pacific Microwave Photonics Conference (AP-MWP 2007)　C-3　2007/04
A mode-locked laser-type optical atomic clock with an optically pumped Cs gas cell Peer-reviewed

T. Hirayama, M. Yoshida, M. Nakazawa, K. Hagimoto, T. Ikegami

Asia-Pacific Microwave Photonics Conference (AP-MWP 2007)　D-38　2007/04
4 x 10 Gb/s WDM transmission over a 5-km-long photonic crystal fiber in the 800-nm region Peer-reviewed

Yosuke Oikawa, Hideaki Hasegawa, Kenya Suzuki, Yasuyuki Inoue, Toshihiko Hirooka, Masataka Nakazawa

IEEE PHOTONICS TECHNOLOGY LETTERS　19　(5-8)　613-615　2007/03

DOI： 10.1109/LPT.2007.894354 　

ISSN： 1041-1135
Ultra-stable regeneratively mode-locked laser as an opto-electronic microwave oscillator and its application to optical metrology Peer-reviewed

Masataka Nakazawa, Masato Yoshida, Toshihiko Hirooka

IEICE TRANSACTIONS ON ELECTRONICS　E90C　(2)　443-449　2007/02

DOI： 10.1093/ietele/e90-c.2.443 　

ISSN： 0916-8524

eISSN： 1745-1353
Optical phase-locked loop for coherent transmission over 500km using heterodyne detection with fiber lasers Peer-reviewed

Keisuke Kasai, Jumpei Hongo, Masato Yoshida, Masataka Nakazawa

IEICE ELECTRONICS EXPRESS　4　(3)　77-81　2007/02

DOI： 10.1587/elex.4.77 　

ISSN： 1349-2543
A C₂H₂ frequency-stabilized erbium-doped fiber laser and its application to coherent communication

Masato Yoshida, Keisuke Kasai, Jumpei Hongo, Masataka Nakazawa

FIBER LASERS IV: TECHNOLOGY, SYSTEMS, AND APPLICATIONS　6453　2007

DOI： 10.1117/12.714489 　

ISSN： 0277-786X
Polarization-multiplexed 1 Gsymbol/s, 64 QAM (12 Gbit/s) coherent optical transmission over 150 km with an optical bandwidth of 2 GHz

Masataka Nakazawa, Jumpei Hongo, Keisuke Kasai, Masato Yoshida

Optics InfoBase Conference Papers　2007
Publisher: Optical Society of America
ISSN： 2162-2701
1.5 μm ¹³C₂H₂ frequency-stabilized fiber laser and its application to QAM coherent transmission with high spectral efficiency

Tohoku-Section Joint Convention Record of Institutes of Electrical and Information Engineers, Japan　2007　(0)　29-29　2007
Publisher: Organizing Committee of Tohoku-Section Joint Convention of Institutes of Electrical and Information Engineers, Japan
DOI： 10.11528/tsjc.2007.0_29 　
9.1926-GHz再生モード同期ファイバレーザを用いた高安定Cs光原子時計

平山徹, 矢加部正嗣, 吉田真人, 中沢正隆, 古賀保喜, 萩本憲

電子情報通信学会論文誌 C　J90-C　(12)　2007

ISSN： 1345-2827
10 Gbit/s 2 km photonic crystal fibre transmission with 850 nm directly modulated singlemode VCSEL Peer-reviewed

H. Hasegawa, Y. Oikawa, M. Nakazawa

ELECTRONICS LETTERS　43　(2)　117-119　2007/01

DOI： 10.1049/el:20073781 　

ISSN： 0013-5194
Optical phase-locked loop for coherent transmission over 500 km Peer-reviewed

K. Kasai, M. Yoshida, M. Nakazawa

Optical Fiber Communication Conference (OFC 2007)　JWA49　2007

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通研インポート200703
1 Gsymbol/s, 64 QAM coherent optical transmission over 150 km with a spectral efficiency of 3 bit/s/Hz Peer-reviewed

Jumpei Hongou, Keisuke Kasai, Masato Yoshida, Masataka Nakazawa

OFC/NFOEC 2007 - Optical Fiber Communication and the National Fiber Optic Engineers Conference 2007　OMP3　2007

DOI： 10.1109/OFC.2007.4348615 　
A mode-hop-free, frequency-tunable 40 GHz mode-locked fiber laser Peer-reviewed

Masato Yshida, Keisuke Kasai, Masataka Nakazawa

OFC/NFOEC 2007 - Optical Fiber Communication and the National Fiber Optic Engineers Conference 2007　OTuF3　2007

DOI： 10.1109/OFC.2007.4348785 　
A C2H2 frequency-stabilized erbium-doped fiber laser and its application to coherent communication Peer-reviewed

Masato Yoshida, Keisuke Kasai, Jumpei Hongo, Masataka Nakazawa

FIBER LASERS IV: TECHNOLOGY, SYSTEMS, AND APPLICATIONS　6453　6453-85　2007

DOI： 10.1117/12.714489 　

ISSN： 0277-786X
Next generation ultrafast telecommunications technologies Invited Peer-reviewed

Masataka Nakazawa

Conference on Lasers and Electro-Optics Europe - Technical Digest　Invited paper, TF1-3TUE　2007

DOI： 10.1109/CLEOE-IQEC.2007.4387086 　
10 Gbit/s 2 km photonic crystal fibre transmission with 850 nm directly modulated singlemode VCSEL Peer-reviewed

H. Hasegawa, Y. Oikawa, M. Nakazawa

Electronics Letters　43　(2)　117-119　2007

DOI： 10.1049/el:20073781 　

ISSN： 0013-5194
QAM based coherent transmission technologies using DSP Invited Peer-reviewed

Masataka Nakazawa

2007 DIGEST OF THE LEOS SUMMER TOPICAL MEETINGS　47-48　2007

DOI： 10.1109/LEOSST.2007.4288324 　
Terabit OTDM transmission - Key challenges Invited Peer-reviewed

Masataka Nakazawa, Toshihiko Hirooka

2007 DIGEST OF THE LEOS SUMMER TOPICAL MEETINGS　230-231　2007

DOI： 10.1109/LEOSST.2007.4288418 　
A polarization-maintained, ultranarrow FBG filter with a linewidth of 1.3 GHz Peer-reviewed

Akihito Suzuki, Youhei Takahashi, Masataka Nakazawa

IEICE ELECTRONICS EXPRESS　3　(22)　469-473　2006/11

DOI： 10.1587/elex.3.469 　

ISSN： 1349-2543
Performance improvement of an acetylene (C2H2) frequency-stabilized fiber laser Peer-reviewed

Keisuke Kasai, Akihito Suzuki, Masato Yoshida, Masataka Nakazawa

IEICE ELECTRONICS EXPRESS　3　(22)　487-492　2006/11

DOI： 10.1587/elex.3.487 　

ISSN： 1349-2543
160-Gb/s-600-km OTDM transmission using time-domain optical Fourier transformation Peer-reviewed

Toshihiko Hirooka, Ken-Ichi Hagiuda, Takashi Kumakura, Kou Osawa, Masataka Nakazawa

IEEE PHOTONICS TECHNOLOGY LETTERS　18　(21-24)　2647-2649　2006/11

DOI： 10.1109/LPT.2006.887770 　

ISSN： 1041-1135
Comparison of 40GHz optical demultiplexers using SMZ switch and EA modulator in 160Gbit/s-500km OTDM transmission Peer-reviewed

Toshihiko Hirooka, Takashi Kumakura, Kou Osawa, Masataka Nakazawa

IEICE ELECTRONICS EXPRESS　3　(17)　397-403　2006/09

DOI： 10.1587/elex.3.397 　

ISSN： 1349-2543
Robust and low-noise fiber based frequency comb for long-term measurement of optical frequencies Peer-reviewed

H. Inaba, Y. Daimon, F. L. Hong, A. Onae, K. Minoshima, T. R. Schibli, M. Onishi, T. Okuno, M. Hirano, M. Nakazawa, H. Matsumoto

CPEM2006 Digest　430-431　2006/07
Optical adaptive equalization of high-speed signals using time-domain optical Fourier transformation Peer-reviewed

Toshihiko Hirooka, Masataka Nakazawa

JOURNAL OF LIGHTWAVE TECHNOLOGY　24　(7)　2530-2540　2006/07

DOI： 10.1109/JLT.2006.874647 　

ISSN： 0733-8724
Long-term measurement of optical frequencies using a simple, robust and low-noise fiber based frequency comb Peer-reviewed

H Inaba, Y Daimon, FL Hong, A Onae, K Minoshima, TR Schibli, H Matsumoto, M Hirano, T Okuno, M Onishi, M Nakazawa

OPTICS EXPRESS　14　(12)　5223-5231　2006/06

DOI： 10.1364/OE.14.005223 　

ISSN： 1094-4087
20 Msymbol/s, 64 and 128 QAM coherent optical transmission over 525 km using heterodyne detection with frequency-stabilised laser Peer-reviewed

M. Nakazawa, M. Yoshida, K. Kasai, J. Hongou

ELECTRONICS LETTERS　42　(12)　710-712　2006/06

DOI： 10.1049/el:20060646 　

ISSN： 0013-5194
Polymer saturable absorber materials in the 1.5 mu m band using poly-methyl-methacrylate and polystyrene with single-wall carbon nanotubes and their application to a femtosecond laser Peer-reviewed

M Nakazawa, S Nakahara, T Hirooka, M Yoshida

OPTICS LETTERS　31　(7)　915-917　2006/04

DOI： 10.1364/OL.31.000915 　

ISSN： 0146-9592
10Gb/s transmission over 5 km at 850nm using single-mode photonic crystal fiber, single-mode VCSEL, and Si-APD Peer-reviewed

Hideaki Hasegawa, Yosuke Oikawa, Masato Yoshida, Toshihiko Hirooka, Masataka Nakazawa

IEICE ELECTRONICS EXPRESS　3　(6)　109-114　2006/03

DOI： 10.1587/elex.3.109 　

ISSN： 1349-2543
ABCD matrix formalism of time-domain optical Fourier transformation for distortion-free pulse transmission Peer-reviewed

Masataka Nakazawa, Toshihiko Hirooka

IEICE ELECTRONICS EXPRESS　3　(4)　74-79　2006/02

DOI： 10.1587/elex.3.74 　

ISSN： 1349-2543
10 Gb/s x 4 channel WDM transmission over a 3 km-long photonic crystal fiber in the 800 nm region

Tohoku-Section Joint Convention Record of Institutes of Electrical and Information Engineers, Japan　2006　(0)　13-13　2006
Publisher: Organizing Committee of Tohoku-Section Joint Convention of Institutes of Electrical and Information Engineers, Japan
DOI： 10.11528/tsjc.2006.0_13 　
Fiber transmission of microwave and optical standard signals using a mode-locked fiber laser in the GHz region

Tohoku-Section Joint Convention Record of Institutes of Electrical and Information Engineers, Japan　2006　(0)　14-14　2006
Publisher: Organizing Committee of Tohoku-Section Joint Convention of Institutes of Electrical and Information Engineers, Japan
DOI： 10.11528/tsjc.2006.0_14 　
An acetylene ((C2H2)-C-13) stabilized single-polarization fiber laser Peer-reviewed

Keisuke Kasai, Masato Yoshida, Masataka Nakazawa

ELECTRONICS AND COMMUNICATIONS IN JAPAN PART II-ELECTRONICS　89　(10)　9-17　2006

DOI： 10.1002/ecjb.20235 　

ISSN： 8756-663X
10 Gb/s transmission over 3 km at 850 nm using single-mode photonic crystal fiber, single-mode VCSEL, and Si-APD Peer-reviewed

Hideaki Hasegawa, Yosuke Oikawa, Toshihiko Hirooka, Masato Yoshida, Masataka Nakazawa

2006 OPTICAL FIBER COMMUNICATION CONFERENCE/NATIONAL FIBER OPTIC ENGINEERS CONFERENCE, VOLS 1-6　1822-1824　2006
Measurements of longitudinal linewidth and relative intensity noise in ultrahigh-speed mode-locked semiconductor lasers Peer-reviewed

K Haneda, M Yoshida, H Yokoyama, Y Ogawa, M Nakazawa

ELECTRONICS AND COMMUNICATIONS IN JAPAN PART II-ELECTRONICS　89　(2)　28-36　2006

DOI： 10.1002/ecjb.20185 　

ISSN： 8756-663X
Characteristics of CPT signals of Cs-D₁ and Cs-D₂ lines Peer-reviewed

K. Hagimoto, T. Hirayama, K. Watanabe, T. Ikegami, S. Ohshima, M. Yoshida, M. Nakazawa

Workshop on Chirp Scale Atomic Clock: Status and Potentiality　38751　2006

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通研ＤＢインポート
A (C2H2)-C-13 frequency-stabilized, polarization-maintained 1.54 mu m erbium fiber ring laser with a new feedback system Peer-reviewed

Keisuke Kasai, Masato Yoshida, Masataka Nakazawa

2006 OPTICAL FIBER COMMUNICATION CONFERENCE/NATIONAL FIBER OPTIC ENGINEERS CONFERENCE, VOLS 1-6　866-868　2006
Polymer saturable absorber materials in 1.5 mu m band using PMMA and PS with single-wall carbon nanotubes Peer-reviewed

Masataka Nakazawa, Seiji Nakahara, Toshihiko Hirooka, Masato Yoshida, Toshikuni Kaino, Kyoji Komatsu

2006 OPTICAL FIBER COMMUNICATION CONFERENCE/NATIONAL FIBER OPTIC ENGINEERS CONFERENCE, VOLS 1-6　2154-+　2006
Recent progress and future prospects for high-speed optical transmission technology using an ultrashort optical pulse train (Invited Paper) Peer-reviewed

M. Nakazawa, T. Hirooka

IEICE Transactions on Communications　J89-B　(11)　2067-2081　2006

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通研インポート200703
Ultra-broadband dispersion measurement of photonic crystal fiber with pico-second streak camera and group-delay-free supercontinuum Peer-reviewed

Y. Oikawa, H. Hasegawa, T. Hirooka, M. Yoshida, M. Nakazawa

IEICE Transactions on Electronics (in Japanese)　J89-C　(7)　450-457　2006
Publisher: The Institute of Electronics, Information and Communication Engineers
ISSN： 1345-2827

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通研インポート200703
Regeneratively mode-locked laser as an opto-electronic microwave oscillator and its application to optical metrology (Invited Paper) Peer-reviewed

M. Nakazawa

2006 Asia-Pacific Microwave Photonics Conference (AP-MWP2006)　K-1　2006

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通研インポート200703
An ultra-low noise and narrow linewidth λ/4-shifted DFB Er-doped fiber laser with a ring configuration Peer-reviewed

Akihito Suzuki, Youhei Takahashi, Masato Yoshida, Masataka Nakazawa

2006 European Conference on Optical Communications Proceedings, ECOC 2006　Th2.3.2　2006

DOI： 10.1109/ECOC.2006.4800962 　
Polarization-maintained, ultranarrow FBG filter with 1.3 GHz linewidth Peer-reviewed

A. Suzuki, Y. Takahashi, M. Nakazawa

European Optical Society Annual Meeting 2006, Topical Meeting on Extreme Optics (TOM 2)　66-67　2006

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通研インポート200703
A 1.54 #Gmu#GRm ¹³C₂H₂ frequency-stabilized, single-polarization fiber ring laser Peer-reviewed

K. Kasai, M. Yoshida, M. Nakazawa

European Optical Society Annual Meeting 2006, Topical Meeting on Extreme Optics (TOM 2)　94-95　2006

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通研インポート200703
10 Gb/s x 4 channel WDM transmission over 3 km in the 800 nm region using photonic crystal fibers Peer-reviewed

H. Hasegawa, Y. Oikawa, T. Hirooka, M. Yoshida, K. Suzuki, Y. Inoue, M. Nakazawa

European Conference on Optical Communication (ECOC 2006)　We4.5.4　2006

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通研インポート200703
Ultrahigh-speed fiber laser and its application to optical metrology Peer-reviewed

Masataka Nakazawa

Conference on Lasers and Electro-Optics and 2006 Quantum Electronics and Laser Science Conference, CLEO/QELS 2006　CTuV4　2006

DOI： 10.1109/CLEO.2006.4628299 　
Distortion-free optical transmission using time-domain optical Fourier transformation and transform-limited optical pulses Peer-reviewed

M Nakazawa, T Hirooka

JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS　22　(9)　1842-1855　2005/09

DOI： 10.1364/JOSAB.22.001842 　

ISSN： 0740-3224
Ultrastable cesium atomic clock with a 9.1926-GHz regeneratively mode-locked fiber laser Peer-reviewed

M Yakabe, K Nito, M Yoshida, M Nakazawa, Y Koga, K Hagimoto, T Ikegami

OPTICS LETTERS　30　(12)　1512-1514　2005/06

DOI： 10.1364/OL.30.001512 　

ISSN： 0146-9592
Linewidth and relative intensity noise measurements of longitudinal modes in ultrahigh-speed mode-locked laser diodes Peer-reviewed

K Haneda, M Yoshida, M Nakazawa, H Yokoyama, Y Ogawa

OPTICS LETTERS　30　(9)　1000-1002　2005/05

DOI： 10.1364/OL.30.001000 　

ISSN： 0146-9592

eISSN： 1539-4794
40-GHz, 100-fs stimulated-Brillouin-scattering-free pulse generation by combining a mode-locked laser diode and a dispersion-decreasing fiber Peer-reviewed

K Hagiuda, T Hirooka, M Nakazawa

OPTICS LETTERS　30　(6)　670-672　2005/03

DOI： 10.1364/OL.30.000670 　

ISSN： 0146-9592
Stimulated Brillouin scattering in dispersion-decreasing fiber with ultrahigh-speed femtosecond soliton pulse compression Peer-reviewed

T Hirooka, S Ono, K Hagiuda, M Nakazawa

OPTICS LETTERS　30　(4)　364-366　2005/02

DOI： 10.1364/OL.30.000364 　

ISSN： 0146-9592
A new ultrastable cesium optical atomic clock with a 9.1926-GHz regeneratively mode-locked fiberlaser Peer-reviewed

M Yakabe, K Nito, M Yoshida, M Nakazawa, Y Koga, K Hagimoto, T Ikegami

ULTRAFAST PHENOMENA XIV　79　831-833　2005

ISSN： 0172-6218
Photon number squeezing of ultrabroadband pulses generated by microstructure fibers Peer-reviewed

H Furumochi, A Tada, K Hirosawa, F Kannari, M Takeoka, M Nakazawa

ULTRAFAST PHENOMENA XIV　79　873-875　2005

ISSN： 0172-6218
Linewidth and RIN measurements of longitudinal modes in ultrahigh-speed mode-locked laser diodes Peer-reviewed

K Haneda, H Yokoyama, Y Ogawa, M Nakazawa

ULTRAFAST PHENOMENA XIV　79　780-782　2005

ISSN： 0172-6218
Stimulated Brillouin scattering in ultrahigh-speed femtosecond soliton pulse compression with a dispersion-decreasing fiber Peer-reviewed

T Hirooka, S Ono, KI Hagiuda, M Nakazawa

ULTRAFAST PHENOMENA XIV　79　43-45　2005

ISSN： 0172-6218
Optimization of a 40 GHz regeneratively and harmonically mode-locked fiber laser under PLL operation and its longitudinal mode characteristics Peer-reviewed

M Yoshida, T Yaguchi, S Harada, M Nakazawa

ULTRAFAST PHENOMENA XIV　79　765-767　2005

ISSN： 0172-6218
Measurements of longitudinal linewidth and relative intensity noise in ultrahigh-speed mode-locked semiconductor lasers Peer-reviewed

K. Haneda, M. Yoshida, H. Yokoyama, Y. Ogawa, M. Nakazawa

IEICE Trans. Electron. (in Japanese)　J88-C　(3)　161-168　2005

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Distortion-free optical fiber transmission of ultrashort optical pulses using time-domain optical Fourier transformation Peer-reviewed

M. Nakazawa, T. Hirooka

Japanese Journal of Optics (in Japanese)　(1)　26-31　2005

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Microwave frequency tuning characteristics of an opto-microwave oscillator made of fiber laser and its application to Ramsey fringe observation Peer-reviewed

M. Yakabe, K. Nito, M. Yoshida, M. Nakazawa

IEICE Trans. Comm. (in Japanese)　J88-B　(9)　1829-1836　2005

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Observation of optimum air-hole tapering of splicing between a conventional fiber and a photonic crystal fiber and analysis of reduction of Fresnel reflection Peer-reviewed

H. Hasegawa, M.Kikegawa, M. Yoshida, T. Hirooka, M. Nakazawa

IEICE Trans. Electron. (in Japanese)　J88-C　(10)　779-787　2005

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Acetylene (¹³C₂H₂) stabilized single-polarization fiber laser Peer-reviewed

K. Kasai, M. Yoshida, M. Nakazawa

IEICE Trans. Electron. (in Japanese)　J88-C　(9)　708-715　2005

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A new method for optimum dispersion designing of zero-dispersion and dispersion-flattened photonic crystal fibers Peer-reviewed

H. Hasegawa, T. Hirooka, M. Nakazawa

IEICE Trans. Electron. (in Japanese)　J88-C　(7)　519-527　2005

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Ultrahigh-speed distortion-free optical pulse transmission using time-domain optical Fourier transformation Peer-reviewed

T. Hirooka, M. Nakazawa, F. Futami, S. Watanabe

IEICE Trans. Comm. (in Japanese)　J88-B　(8)　1402-1410　2005

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New optimum dispersion design method for zero-dispersion and dispersion-flattened photonic crystal fibers Peer-reviewed

H Hasegawa, T Hirooka, M Nakazawa

2005 PACIFIC RIM CONFERENCE ON LASERS AND ELECTRO-OPTICS　349-350　2005

DOI： 10.1109/CLEOPR.2005.1569519 　
An ultrastable Cs optical atomic clock with a 9.1926-GHz low-drift regeneratively mode-locked fiber laser Peer-reviewed

T Hirayama, M Yakabe, M Yoshida, M Nakazawa, Y Koga, K Hagimoto

2005 PACIFIC RIM CONFERENCE ON LASERS AND ELECTRO-OPTICS　1025-1026　2005

DOI： 10.1109/CLEOPR.2005.1569864 　
A (C2H2)-C-13 frequency-stabilized, polarization-maintained erbium fiber ring laser with no frequency modulation Peer-reviewed

K Kasai, M Yoshida, M Nakazawa, K Shiota, S Masuda

2005 PACIFIC RIM CONFERENCE ON LASERS AND ELECTRO-OPTICS　295-296　2005

DOI： 10.1109/CLEOPR.2005.1569492 　
An ultrastable Cs optical atomic clock with a laser-type opto-microwave oscillator Peer-reviewed

T. Hirayama, M. Yakabe, M. Yoshida, M. Nakazawa, Y. Koga, K. Hagimoto, T. Ikegami

NMIJ-BIPM Workshop on the Impact of Information Technology in Metrology　2005

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通研ＤＢインポート
Ultrahigh-speed distortion-free transmission using all-optical time-domain Fourier transformation Peer-reviewed

T Hirooka, M Nakazawa

2005 PACIFIC RIM CONFERENCE ON LASERS AND ELECTRO-OPTICS　1001-1002　2005

DOI： 10.1109/CLEOPR.2005.1569852 　
A C₂H₂ frequency-stabilized, single-polarization fiber laser Peer-reviewed

K. Kasai, M. Yoshida, M. Nakazawa

NMIJ-BIPM Workshop on the Impact of Information Technology in Metrology　2005

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通研ＤＢインポート
Ultrastable mode-locked fiber lasers and their application to optical comb delivery through optical fiber networks (Invited paper) Peer-reviewed

M. Nakazawa

NMIJ-BIPM Workshop on the Impact of Information Technology in Metrology　2005

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Derivation of analytical expression for third-order dispersion elimination using time-domain optical Fourier transformation Peer-reviewed

Toshihiko Hirooka, Masataka Nakazawa

IET Conference Publications　2005　(502)　653-654　2005
Publisher: Institution of Engineering and Technology
DOI： 10.1049/cp:20050655 　
An ultrastable PLL mode-locked fiber laser with a hydrogen maser clock Peer-reviewed

M Yoshida, T Hirayama, M Yakabe, M Nakazawa, Y Koga, K Hagimoto

2005 PACIFIC RIM CONFERENCE ON LASERS AND ELECTRO-OPTICS　1027-1028　2005

DOI： 10.1109/CLEOPR.2005.1569865 　
Measurement of longitudinal linewidth broadening of mode-locked lasers during ultrahigh-speed pulse transmission Peer-reviewed

Osawa, K. Haneda, S. Waiyapot, M. Nakazawa

NMIJ-BIPM Workshop on the Impact of Information Technology in Metrology　2005

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Measurement of optical carrier spectrum deformation in high-speed pulse transmission Peer-reviewed

K Osawa, K Haneda, T Hirooka, M Yoshida, S Waiyapot, M Nakazawa

2005 PACIFIC RIM CONFERENCE ON LASERS AND ELECTRO-OPTICS　998-1000　2005

DOI： 10.1109/CLEOPR.2005.1569851 　
Observation of optimum air-hole tapering of splicing between conventional fiber and photonic crystal fiber and analysis of reduction in Fresnel reflection Peer-reviewed

H Hasegawa, M Kikegawa, M Yoshida, T Hirooka, M Nakazawa

2005 PACIFIC RIM CONFERENCE ON LASERS AND ELECTRO-OPTICS　345-346　2005

DOI： 10.1109/CLEOPR.2005.1569517 　
Ultra-broadband dispersion measurement of photonic crystal fiber with pico-second streak camera and group-delay-free supercontinuum Peer-reviewed

Y Oikawa, H Hasegawa, M Yoshida, T Hirooka, M Nakazawa

2005 PACIFIC RIM CONFERENCE ON LASERS AND ELECTRO-OPTICS　337-339　2005

DOI： 10.1109/CLEOPR.2005.1569514 　
New adaptive equalization scheme for 160 Gb/s transmitted signal using time-domain optical Fourier transformation Peer-reviewed

T. Hirooka, M. Nakazawa, F. Futami, S. Watanabe

30th European Conference on Optical Communication　Paper Th1.5.3　2004/09

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<RIEC><DUMMY>あ</DUMMY><BIBID>2003500798</BIBID></RIEC>
A ¹³C₂H₂ frequency-stabilized, polarization-maintained erbium fiber ring laser with no frequency modulation Peer-reviewed

K. Kasai, M. Yoshida, M. Nakazawa

30th European Conference on Optical Communication　Paper Th1.3.5　2004/09

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Generation of a 40-GHz, 100-fs pulse train from a mode-locked laser diode using DDF soliton compression Peer-reviewed

K. Hagiuda, T. Hirooka, S. Ono, M. Yoshida, M. Nakazawa, S. Arahira, Y. Ogawa

30th European Conference on Optical Communication　Paper Tu3.3.2　2004/09

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A 40 GHz regeneratively and harmonically mode-locked erbium-doped fiber laser and its longitudinal-mode characteristics Peer-reviewed

M Yoshida, T Yaguchi, S Harada, M Nakazawa

IEICE TRANSACTIONS ON ELECTRONICS　E87C　(7)　1166-1172　2004/07

ISSN： 0916-8524

eISSN： 1745-1353
Ideal distortion-free transmission using optical Fourier transformation and Fourier transform-limited optical pulses Peer-reviewed

M Nakazawa, T Hirooka, F Futami, S Watanabe

IEEE PHOTONICS TECHNOLOGY LETTERS　16　(4)　1059-1061　2004/04

ISSN： 1041-1135
Gaussian and sech approximations of mode field profiles in photonic crystal fibers Peer-reviewed

T Hirooka, Y Hori, M Nakazawa

IEEE PHOTONICS TECHNOLOGY LETTERS　16　(4)　1071-1073　2004/04

ISSN： 1041-1135
Parabolic pulse generation by use of a dispersion-decreasing fiber with normal group-velocity dispersion Peer-reviewed

T Hirooka, M Nakazawa

OPTICS LETTERS　29　(5)　498-500　2004/03

ISSN： 0146-9592
Ultrafast optical pulses and solitons for advanced communications Invited Peer-reviewed

M. Nakazawa

Pacific Rim Conference on Lasers and Electro-Optics, Invited paper, Tu3G-(6)-1　2003/12

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Ideal distortion-free transmission using optical Fourier transformation and transform-limited ultrashort pulses Peer-reviewed

M. Nakazawa, T. Hirooka, F. Futami, S. Watanabe

European Conference on Optical Communication, Post-deadline paper, Th4.3.8　2003/09

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Ultrahigh speed optical transmission using femtosecond pulses and emerging new technology Invited Peer-reviewed

M. Nakazawa

Europe-U.S.-Japan Symposium on Ultrafast Photonic Technology, Invited paper　2003/07

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1.28 Tbit/s-70-km OTDM femtosecond-pulse transmission using third- and fourth-order simultaneous dispersion compensation with a phase modulator Peer-reviewed

T Yamamoto, KR Tamura, M Nakazawa

ELECTRONICS AND COMMUNICATIONS IN JAPAN PART I-COMMUNICATIONS　86　(3)　68-79　2003

DOI： 10.1002/ecja.10028 　

ISSN： 8756-6621
Origin of group delay ripple in chirped fiber Bragg gratings and its effective reduction method Peer-reviewed

T Komukai, T Inui, M Nakazawa

ELECTRONICS AND COMMUNICATIONS IN JAPAN PART II-ELECTRONICS　86　(8)　76-84　2003

DOI： 10.1002/ecjb.10007 　

ISSN： 8756-663X
Observation of acetylene molecular absorption line with tunable, single-frequency, and mode-hop-free erbium-doped fiber ring laser Peer-reviewed

H Inaba, A Onae, Y Akimoto, T Komukai, M Nakazawa

IEEE JOURNAL OF QUANTUM ELECTRONICS　38　(10)　1325-1330　2002/10

DOI： 10.1109/JQE.2002.802959 　

ISSN： 0018-9197

eISSN： 1558-1713
Adaptive dispersion slope equalizer using a nonlinearly chirped fiber Bragg grating pair with a novel dispersion detection technique Peer-reviewed

T Inui, T Komukai, M Nakazawa, K Suzuki, KR Tamura, K Uchiyama, T Morioka

IEEE PHOTONICS TECHNOLOGY LETTERS　14　(4)　549-551　2002/04

DOI： 10.1109/68.992607 　

ISSN： 1041-1135
100 km transmission of a 640 Gbitls OTDM signal using femtosecond pulses Peer-reviewed

T Yamamoto, E Yoshida, KR Tamura, M Nakazawa

ELECTRONICS AND COMMUNICATIONS IN JAPAN PART I-COMMUNICATIONS　85　(5)　48-56　2002

ISSN： 8756-6621
Ultrahigh-speed OTDM transmission beyond 1 tera bit-per-second using a femtosecond pulse train Peer-reviewed

M Nakazawa, T Yamamoto, KR Tamura

IEICE TRANSACTIONS ON ELECTRONICS　E85C　(1)　117-125　2002/01

ISSN： 0916-8524

eISSN： 1745-1353
フォトニック結晶ファイバ Peer-reviewed

中沢正隆

レーザー研究　30　(8)　426-434　2002

DOI： 10.2184/lsj.30.426 　
100 km transmission of a 640 Gbitls OTDM signal using femtosecond pulses Peer-reviewed

T Yamamoto, E Yoshida, KR Tamura, M Nakazawa

ELECTRONICS AND COMMUNICATIONS IN JAPAN PART I-COMMUNICATIONS　85　(5)　48-56　2002

DOI： 10.1002/ecja.1096 　

ISSN： 8756-6621
Recent progress on photonic crystal fibers Peer-reviewed

Masataka Nakazawa

3rd Chitose International Forum on Photonics Science & Technology　105-106 (IV-5)　2002
Ultrafast optical TDM transmission with the use of novel nonlinear optical fiber devices Peer-reviewed

Masataka Nakazawa

Nonlinear Guided Waves and Their Applications 2002　NLTuC1-1-NLTuC1-3　2002
Ultrafast optical TDM transmission with the use of femtosecond pulses Peer-reviewed

Masataka Nakazawa

Nonlinear Optics 2002　69-71 (TuA2)　2002
Longitudinal linewidth measurement of 10 GHz, picosecond mode-locked erbium-doped fiber lasers using a heterodyne detection method Peer-reviewed

Masato Yoshida, Choi Samuel, Masataka Nakazawa

The 9th International Workshop on Femtosecond Technology　155 (FC-3)　2002
A discretely tunable mode-locked laser with 32 wavelengths and 100-GHz channel spacing using an arrayed waveguide grating Peer-reviewed

KR Tamura, Y Inoue, K Sato, T Komukai, A Sugita, M Nakazawa

IEEE PHOTONICS TECHNOLOGY LETTERS　13　(11)　1227-1229　2001/11

ISSN： 1041-1135
54-fs, 10-GHz soliton generation from a polarization-maintaining dispersion-flattened dispersion-decreasing fiber pulse compressor Peer-reviewed

K. R. Tamura, M. Nakazawa

Optics Letters　26　(11)　762-764　2001/06/01
Publisher: Optical Society of America (OSA)
DOI： 10.1364/OL.26.000762 　

ISSN： 0146-9592
A polarization-maintaining pedestal-free femtosecond pulse compressor incorporating an ultrafast dispersion-imbalanced nonlinear optical loop mirror Peer-reviewed

K. R. Tamura, M. Nakazawa

IEEE Photonics Technology Letters　13　(5)　526-528　2001/05

DOI： 10.1109/68.920774 　

ISSN： 1041-1135
Third- and fourth-order active dispersion compensation with a phase modulator in a terabit-per-second optical time-division multiplexed transmission Peer-reviewed

T Yamamoto, M Nakazawa

OPTICS LETTERS　26　(9)　647-649　2001/05

DOI： 10.1364/OL.26.000647 　

ISSN： 0146-9592
Cesium optical atomic clock: an optical pulse that tells the time Peer-reviewed

M Nakazawa, K Suzuki

OPTICS LETTERS　26　(9)　635-637　2001/05

DOI： 10.1364/OL.26.000635 　

ISSN： 0146-9592
Low-loss, 2km-long photonic crystal fiber with zero GVD in the near IR suitable for picosecond pulse propagation at the 800 nm band Peer-reviewed

H. Kubota, K. Suzuki, S. Kawanishi, M. Nakazawa, M. Tanaka, M. Fujita

CLEO 2001　CPD3　2001/05
A mode-locked frequency-shifted feedback fiber laser Peer-reviewed

M. Yoshida, M. Fujimoto, M. Nakazawa, H. Ito

CLEO 2001　CWA50　2001/05
Highly efficient tunable fiber Bragg grating filters using multilayer piezoelectric transducers Peer-reviewed

T Inui, T Komukai, M Nakazawa

OPTICS COMMUNICATIONS　190　(1-6)　1-4　2001/04

DOI： 10.1016/S0030-4018(01)00987-7 　

ISSN： 0030-4018
Propagation of a solitonlike nonlinear pulse in average normal group-velocity dispersion and its unsuitability for high-speed, long-distance optical transmission Peer-reviewed

M Nakazawa, A Sahara, H Kubota

JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS　18　(4)　409-418　2001/04

DOI： 10.1364/JOSAB.18.000409 　

ISSN： 0740-3224
Very low group delay ripple characteristics of fibre Bragg grating with chirp induced by an S-curve bending technique Peer-reviewed

T Komukai, T Inui, M Nakazawa

ELECTRONICS LETTERS　37　(7)　449-451　2001/03

ISSN： 0013-5194
32 wavelength tunable mode-locked laser with 100 GHz channel spacing using an arrayed waveguide grating Peer-reviewed

K. R. Tamura, Y. Inoue, K. Sato, T. Komukai, A. Sugita, M. Nakazawa

OFC 2001　2　TuJ5　2001/03
1 Tb/s(40 Gb/s x 25 channel)DWDM quasi-DM soliton transmission over 1,500 km using dispersion-managed single-mode fiber and conventional C-band EDFAs Invited Peer-reviewed

K. Suzuki, H. Kubota, M. Nakazawa

OFC 2001　TuN7　2001/03
Third-and fourth-order active dispersion compensation using a phase modulator in a terabit/s OTDM transmission Peer-reviewed

T. Yamamoto, M. Nakazawa

OFC 2001　WH6　2001/03
High sensitivity waveform measurement of 160 Gbit/s signal with optical sampling using quasi-phasematched mixing in LiNbO₃ waveguide Peer-reviewed

S. Kawanishi, T. Yamamoto, M. Nakazawa

OFC 2001　37　(13)　WY6-844　2001/03
Ultrashort optical pulse transmission characteristics of vertically coupled microring resonator add/drop filter Peer-reviewed

S Suzuki, Y Kokubun, M Nakazawa, T Yamamoto, ST Chu

JOURNAL OF LIGHTWAVE TECHNOLOGY　19　(2)　266-271　2001/02

DOI： 10.1109/50.917900 　

ISSN： 0733-8724
Adaptive dispersion slope equalizer for dispersion-shifted fibers using a nonlinearly chirped fiber Bragg grating pair Peer-reviewed

T Inui, T Komukai, M Nakazawa, K Suzuki, KR Tamura, K Uchiyama, T Morioka

CLEO(R)/PACIFIC RIM 2001, POSTDEADLINE PAPER　14-15　2001
Ultrahigh speed OTDM transmission using femtosecond pulses Peer-reviewed

M Nakazawa, T Yamamoto, K Tamura

CLEO(R)/PACIFIC RIM 2001, VOL I, TECHNICAL DIGEST　618-619　2001
Ultrabroad band white light generation from a multimode photonic bandgap fiber with an air core Peer-reviewed

K Suzuki, M Nakazawa

CLEO(R)/PACIFIC RIM 2001, POSTDEADLINE PAPER　24-25　2001
40Gbit/s return-to-zero transmission over 500km of standard fibre using chirped fibre Bragg gratings with small group delay ripples Peer-reviewed

A Sahara, T Komukai, E Yamada, M Nakazawa

ELECTRONICS LETTERS　37　(1)　8-9　2001/01

DOI： 10.1049/el:20010006 　

ISSN： 0013-5194
40Gbit/s return-to-zero transmission over 500km of standard fibre using chirped fibre Bragg gratings with small group delay ripples Peer-reviewed

A Sahara, T Komukai, E Yamada, M Nakazawa

ELECTRONICS LETTERS　37　(1)　8-9　2001/01

ISSN： 0013-5194
A 40-GHz 850-fs regeneratively FM mode-locked polarization-maintaining erbium fiber ring laser Peer-reviewed

M Nakazawa, E Yoshida

IEEE PHOTONICS TECHNOLOGY LETTERS　12　(12)　1613-1615　2000/12

DOI： 10.1109/68.896324 　

ISSN： 1041-1135
A wavelength-tunable dispersion equalizer using a nonlinearly chirped fiber Bragg grating pair mounted on multilayer piezoelectric transducers Peer-reviewed

T Inui, T Komukai, M Nakazawa

IEEE PHOTONICS TECHNOLOGY LETTERS　12　(12)　1668-1670　2000/12

DOI： 10.1109/68.896343 　

ISSN： 1041-1135
Toward a terabit/sec single-channel OTDM transmission(招待講演) Invited Peer-reviewed

M. Nakazawa, T. Yamamoto, K. R. Tamura

Microwave Workshops and Exhibition 2000　WS10-5　2000/12
1.28Tbit/s-70 km OTDM transmission using third- and fourth-order simultaneous dispersion compensation with a phase modulator Peer-reviewed

M Nakazawa, T Yamamoto, KR Tamura

ELECTRONICS LETTERS　36　(24)　2027-2029　2000/11

DOI： 10.1049/el:20001391 　

ISSN： 0013-5194
Solitons for breaking barriers to terabit/second WDM and OTDM transmission in the next millennium Peer-reviewed

M Nakazawa

IEEE JOURNAL OF SELECTED TOPICS IN QUANTUM ELECTRONICS　6　(6)　1332-1343　2000/11

DOI： 10.1109/2944.902187 　

ISSN： 1077-260X

eISSN： 1558-4542
40-Gb/s RZ transmission over a transoceanic distance in a dispersion managed standard fiber using a modified inline synchronous modulation method Peer-reviewed

A Sahara, T Inui, T Komukai, H Kubota, M Nakazawa

JOURNAL OF LIGHTWAVE TECHNOLOGY　18　(10)　1364-1373　2000/10

DOI： 10.1109/50.887187 　

ISSN： 0733-8724

eISSN： 1558-2213
The tolerance of the strength of dispersion map in the dispersion managed soliton system with the synchronous modulation Peer-reviewed

A. Sahara, H. Kubota, M. Nakazawa

ROSC International Workshop 2000　2000/10
640 Gb/s(40 Gb/s x 16 channel)-1,000 km dense WDM dispersion-managed soliton transmission Peer-reviewed

K. Suzuki, H. Kubota, M. Nakazawa

ROSC 2000　2000/10
Recent progress in soliton transmission technology Peer-reviewed

M Nakazawa, H Kubota, K Suzuki, E Yamada, A Sahara

CHAOS　10　(3)　486-514　2000/09

DOI： 10.1063/1.1311394 　

ISSN： 1054-1500
1.28 Tbit/s-70 km optical transmission using third-and forth-order simultaneous dispersion compensation with a phase modulator Peer-reviewed

M. Nakazawa, T. Yamamoto, K. R. Tamura

ECOC 2000(European Conference on Optical Communication)　26　2.5　2000/09
Fundamentals of stable continuum generation at high repetition rates Peer-reviewed

KR Tamura, H Kubota, M Nakazawa

IEEE JOURNAL OF QUANTUM ELECTRONICS　36　(7)　773-779　2000/07

DOI： 10.1109/3.848347 　

ISSN： 0018-9197
Group delay ripple reduction and reflectivity increase in a chirped fiber Bragg crating by multiple-overwriting of a phase mask with an electron-beam Peer-reviewed

T Komukai, T Inui, M Nakazawa

IEEE PHOTONICS TECHNOLOGY LETTERS　12　(7)　816-818　2000/07

DOI： 10.1109/68.853510 　

ISSN： 1041-1135
Large capacity soliton transmission using optical TDM technology(招待講演) Invited Peer-reviewed

M. Nakazawa

OECC 2000　13A2-1　2000/07
Ultra-short pulse transmission characteristics of a vertically coupled microring resonator Add/Drop filter Peer-reviewed

S. Suzuki, Y. Kokubun, M. Nakazawa, T. Yamamoto, S. T. Chu

OECC 2000　14B2-3　2000/07
A wavelength tunable dispersion equalizer using a nonlinearly chirped fiber Bragg grating pair mounted on multi-layer piezoelectric transducers Invited Peer-reviewed

T. Inui, T. Komukai, M. Nakazawa

OECC 2000　14C4-3　2000/07
Experimental observation of mode behavior in erbium-doped optical fiber ring laser Peer-reviewed

H Inaba, Y Akimoto, K Tamura, E Yoshida, T Komukai, M Nakazawa

OPTICS COMMUNICATIONS　180　(1-3)　121-125　2000/06

DOI： 10.1016/S0030-4018(00)00669-6 　

ISSN： 0030-4018
40-Gb/s RZ transmission over transoceanic distance in a dispersion managed standard fiber using a new inline synchronous modulation method Peer-reviewed

A Sahara, T Inui, T Komukai, H Kubota, M Nakazawa

IEEE PHOTONICS TECHNOLOGY LETTERS　12　(6)　720-722　2000/06

DOI： 10.1109/68.849096 　

ISSN： 1041-1135
The design of dispersion equalizers using chirped fiber Bragg gratings Peer-reviewed

T Komukai, T Inui, M Nakazawa

IEEE JOURNAL OF QUANTUM ELECTRONICS　36　(4)　409-417　2000/04

DOI： 10.1109/3.831015 　

ISSN： 0018-9197
640Gbit/s (40 Gbit/s x 16 channel) dispersion-managed DWDM soliton transmission over 1000km with spectral efficiency of 0.4bit/Hz Peer-reviewed

K Suzuki, H Kubota, A Sahara, M Nakazawa

ELECTRONICS LETTERS　36　(5)　443-445　2000/03

ISSN： 0013-5194
640-Gbit/s optical TDM transmission over 92 km through a dispersion-managed fiber consisting of single-mode fiber and "reverse dispersion fiber" Peer-reviewed

T Yamamoto, E Yoshida, KR Tamura, K Yonenaga, M Nakazawa

IEEE PHOTONICS TECHNOLOGY LETTERS　12　(3)　353-355　2000/03

DOI： 10.1109/68.826938 　

ISSN： 1041-1135
Ultrahigh-speed long-distance TDM and WDM soliton transmission technologies Peer-reviewed

M Nakazawa, H Kubota, K Suzuki, E Yamada, A Sahara

IEEE JOURNAL OF SELECTED TOPICS IN QUANTUM ELECTRONICS　6　(2)　363-396　2000/03

DOI： 10.1109/2944.847771 　

ISSN： 1077-260X
Ultra high speed and high capacity optical communication

NAKAZAWA Masataka

rle　20　163-164　2000/01/01
Publisher: The Laser Society of Japan
DOI： 10.2184/lsj.28.Supplement_163 　

ISSN： 0913-6355
80 Gbit/s multi-channel soliton transmission over transoceanic distances Invited Peer-reviewed

M Nakazawa, H Kubota, K Suzuki, E Yamada, A Sahara

MASSIVE WDM AND TDM SOLITON TRANSMISSION SYSTEMS　6　17-39　2000
Handling noise in supercontinuum generation for WDM application Invited Peer-reviewed

H Kubota, KR Tamura, M Nakazawa

MASSIVE WDM AND TDM SOLITON TRANSMISSION SYSTEMS　6　403-410　2000
Simulation method for optical soliton pulse propagation Peer-reviewed

NAKAZAWA Masataka

IECO of Japan　83　866-871　2000
Effect of ASE noise on coherence for supercontinuum light source by soliton compression Peer-reviewed

NAKAZAWA Masataka

Transaction of IEICE of Japan　J83-C　1005-1011　2000
Analyses of coherence-maintained ultrashort optical pulse trains and supercontinuum generation in the presence of soliton-amplified spontaneous-emission interaction Peer-reviewed

H Kubota, KR Tamura, M Nakazawa

JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS　16　(12)　2223-2232　1999/12

ISSN： 0740-3224

eISSN： 1520-8540
A 40-GHz 0.9-ps regeneratively mode-locked fiber laser with a tuning range of 1530-1560 nm Peer-reviewed

E Yoshida, N Shimizu, M Nakazawa

IEEE PHOTONICS TECHNOLOGY LETTERS　11　(12)　1587-1589　1999/12

DOI： 10.1109/68.806855 　

ISSN： 1041-1135
A new optical routing technique with a subcarrier clock controlled wavelength converter Peer-reviewed

KR Tamura, T Komukai, M Nakazawa

IEEE PHOTONICS TECHNOLOGY LETTERS　11　(11)　1491-1493　1999/11

DOI： 10.1109/68.803089 　

ISSN： 1041-1135
Recent progress in soliton communication technology(招待講演) Invited Peer-reviewed

H. Kubota, M. Nakazawa

NOLTA'99(International Symposium on Nonlinear Theory and its Applications)　1-B-1　1999/11
Single channel 640 Gbit/s TDM transmission over 100 km Invited Peer-reviewed

T. Yamamoto, E. Yoshida, K. Tamura, M. Nakazawa

ECOC'99(European Conference on Optical Communication)　II　38-39　1999/09
A new optical routing technique with a subcarrier clock controlled wavelength converter Peer-reviewed

K. Tamura, T. Komukai, M. Nakazawa

ECOC'99(European Conference on Optical Communication)　II　126-127　1999/09
160Gbit/s (80Gbit/s x 2 channels) WDM soliton transmission over 10000 km using in-line synchronous modulation Peer-reviewed

M Nakazawa, K Suzuki, H Kubota

ELECTRONICS LETTERS　35　(16)　1358-1359　1999/08

DOI： 10.1049/el:19990883 　

ISSN： 0013-5194
Pedestal-free pulse compressor for high repetition rate, broadly tunable femtosecond pulses Peer-reviewed

K. Tamura, M. Nakazawa

OAA'99(Optical Amplifier and their Applications)　FA5　1999/06
10 Gbit/s soliton transmission over 2,9000 km using 1.3_m single-mode fibers and dispersion compensation using chirped fiber Bragg gratings Peer-reviewed

E. Yamada, T. Imai, T. Komukai, M. Nakazawa

OAA'99　ThD7　1999/06
Measurement of the timing jitter and pulse energy fluctuation of a PLL regeneratively mode-locked fiber laser Peer-reviewed

E Yoshida, M Nakazawa

IEEE PHOTONICS TECHNOLOGY LETTERS　11　(5)　548-550　1999/05

DOI： 10.1109/68.759394 　

ISSN： 1041-1135
10Gbit/s soliton transmission over 2900km using 1.3 mu m singlemode fibres and dispersion compensation using chirped fibre Bragg gratings Peer-reviewed

E Yamada, T Imai, T Komukai, M Nakazawa

ELECTRONICS LETTERS　35　(9)　728-729　1999/04

DOI： 10.1049/el:19990412 　

ISSN： 0013-5194
Ultrahigh speed soliton and non-soliton technologies(招待講演) Invited Peer-reviewed

M. Nakazawa

UEO'99(Ultrafast Electronics and Optelectronics)　UThA1　1999/04
Efficient optical pulse compression with optical gain via four wave mixing Peer-reviewed

T Yamamoto, M Nakazawa

ELECTRONICS AND COMMUNICATIONS IN JAPAN PART II-ELECTRONICS　82　(3)　41-50　1999/03

ISSN： 8756-663X
Random evolution and coherence degradation of a high-order optical soliton train in the presence of noise Peer-reviewed

M Nakazawa, H Kubota, K Tamura

OPTICS LETTERS　24　(5)　318-320　1999/03

ISSN： 0146-9592
Femtosecond soliton generation over a 32-nm wavelength range using a dispersion-flattened dispersion-decreasing fiber Peer-reviewed

KR Tamura, M Nakazawa

IEEE PHOTONICS TECHNOLOGY LETTERS　11　(3)　319-321　1999/03

DOI： 10.1109/68.748221 　

ISSN： 1041-1135
Spectral-smoothing and pedestal reduction of wavelength tunable quasi-adiabatically compressed femtosecond solitons using a dispersion-flattened dispersion-imbalanced loop mirror Peer-reviewed

KR Tamura, M Nakazawa

IEEE PHOTONICS TECHNOLOGY LETTERS　11　(2)　230-232　1999/02

DOI： 10.1109/68.740713 　

ISSN： 1041-1135
Comparison of the dispersion allocated WDM (10 Gbit/s x 10 channels) optical soliton and NRZ systems using a Q map Peer-reviewed

A Sahara, H Kubota, M Nakazawa

OPTICS COMMUNICATIONS　160　(1-3)　139-145　1999/02

DOI： 10.1016/S0030-4018(98)00641-5 　

ISSN： 0030-4018
Ultra-high speed soliton transmission in presence of polarisation mode dispersion using in-line synchronous modulation Invited Peer-reviewed

A. Sahara, H. Kubota, M. Nakazawa

Electronics Letters　35　(1)　76-78　1999/01/07
Publisher: Institution of Engineering and Technology
DOI： 10.1049/el:19990043 　

ISSN： 0013-5194
Preface for Topical Papers on Ultrahigh Speed and Ultrahigh Capacity Optical Communication Technologies

NAKAZAWA Masataka

rle　27　(4)　230-230　1999
Publisher: The Laser Society of Japan
DOI： 10.2184/lsj.27.230 　

ISSN： 0387-0200
Ultrashort pulse generation using a mode-locked fiber laser

Tamura K., Yoshida E., Nakazawa M.

rle　27　145-146　1999
Publisher: The Laser Society of Japan
DOI： 10.2184/lsj.27.Supplement_145 　

ISSN： 0387-0200
Superb characteristics of dispersion-managed soliton transmission in TDM and WDM systems Peer-reviewed

M Nakazawa, H Kubota, K Suzuki, E Yamada, A Sahara

OPTICAL PULSE AND BEAM PROPAGATION　3609　2-13　1999

ISSN： 0277-786X
A single-frequency and single-polarization fiber ring laser using a 5-GHz fiber Bragg grating Peer-reviewed

Inaba H, Akimoto Y, Tamura K, Yoshida E, Komukai T, Nakazawa M

Electronics and Communications in Japan Part Ii-Electronics　82　(5)　21-29　1999

DOI： 10.1002/(SICI)1520-6432(199905)82:5<21::AID-ECJB3>3.0.CO;2-B 　 10.1002/(sici)1520-6432(199905)82:5<21::aid-ecjb3>3.0.co;2-b 　
Ultra-high speed soliton transmission in presence of polarisation mode dispersion using in-line synchronous modulation Peer-reviewed

A Sahara, H Kubota, M Nakazawa

ELECTRONICS LETTERS　35　(1)　76-78　1999/01

DOI： 10.1049/el:19990043 　

ISSN： 0013-5194
Terabit transmission technologies Peer-reviewed

NAKAZAWA Masataka

NTT R&D Journal Special Issue on Challenges to Terabit/s Communication Technologies　48　43-58　1999
Mode-locked fiber laser technology for ultrahigh-speed TDM optical transmission Peer-reviewed

NAKAZAWA Masataka

NTT R&D Journal Special Issue on Challenges to Terabit/s Communication Technologies　48　59-66　1999
Single-channel 80Gbit/s soliton transmission over 10000km using in-line synchronous modulation Peer-reviewed

M Nakazawa, K Suzuki, H Kubota

ELECTRONICS LETTERS　35　(2)　162-164　1999/01

DOI： 10.1049/el:19990044 　

ISSN： 0013-5194
Demultiplexing of subterabit TDM signal by using ultrafast nonlinear optical loop mirror Peer-reviewed

NAKAZAWA Masataka

IEICE of Japan　J82-C-I　(3)　109-116　1999
Publisher: The Institute of Electronics, Information and Communication Engineers
ISSN： 0915-1893
State-of-the-art and future perspectives of time division multiplexing(TDM)high bit rate optical transmission Peer-reviewed

NAKAZAWA Masataka

The Review of Laser Engineering　27　(4)　231-239　1999
Publisher: The Laser Society of Japan
DOI： 10.2184/lsj.27.231 　

ISSN： 0387-0200

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This paper reviews state-of-the-art technologies that will play important roles in high bit rate transmissionsystems. To take full advantage of fiber capacity, combined multiplexing of WDM (Wavelength Division Multiplexing) and TDM (Time Division Multiplexing) technologies is recommended. Not only device technologies, but also system-side viewpoints are emphasized in order to clarify the differences between TDM and WDM systems. Linear transmission and nonlinear ones, which includes optical soliton systems are comparedfrom such a viewpoint. Short light pulse sources, electrical and optical time-division multiplexing/demultiplexing, timing extraction, dispersion tolerant coding, equalization for second- and third-order dispersionof dispersion-shifted fiber, and optical soliton transmission technologies are described. This paper predictsthat pursuing increased transmission capacity will result in more combined designs of detailed fiberdispersion and transmitted optical signal parameters.
40 Gbit/s soliton transmission field experiment using dispersion management Peer-reviewed

NAKAZAWA Masataka

The Review of Laser Engineering　27　(4)　268-273　1999
Publisher: The Laser Society of Japan
DOI： 10.2184/lsj.27.268 　

ISSN： 0387-0200

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We report 40 Gbit/s soliton transmission field experiments over 1, 000 km in the Tokyo metropolitan optical loop network. The network consists of dispersion-shifted fibers. We employed a dispersion compensation technique to keep the average dispersion at a small constant value of 0.05 ps/km/nm and this resulted in an error-free 5 ps soliton data transmission over 1, 000 km. When in-line synchronous modulation was employed at 680 km, the transmission distance was extended to 1, 360 km.
Ultrashort pulse generation at high repetition rate from mode-locked fiber lasers Peer-reviewed

NAKAZAWA Masataka

The Review of Laser Engineering　27　(4)　274-280　1999
Publisher: The Laser Society of Japan
DOI： 10.2184/lsj.27.274 　

ISSN： 0387-0200

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A stable optical short pulse source with a high repetition rate is very important for realizing future ultrahigh speed optical communication. Of the many potential techniques, an actively mode-locked fiber laser is one of the most attractive sources for generating high quality picosecond pulses at GHz repetition rates. In this paper, we report a regeneratively mode-locked fiber laser which emits a 1-3 ps transform limited pulse at 10 GHz in the 1.53 to 1.55μm wavelength region. This laser can be locked to an external signal by operating a phase-locked loop technique. By using this pulse source and an adiabatic soliton compression technique, a 170 fs pulse train at 10 GHz was generated. Finally, we show the excellent jitter characteristics of the laser.
Design of dispersion equalizers using chirped Bragg gratings Peer-reviewed

NAKAZAWA Masataka

IEICE of Japan　J82-C-I　(6)　359-369　1999
Publisher: The Institute of Electronics, Information and Communication Engineers
ISSN： 0915-1893
Mode-locked fiber ring lasers Peer-reviewed

NAKAZAWA Masataka

The Review of Laser Engineering　27　(11)　756-761　1999
Publisher: The Laser Society of Japan
DOI： 10.2184/lsj.27.756 　

ISSN： 0387-0200

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Mode-locking of fiber lasers is a useful technique for generating a high quality short pulse. An actively modelocked fiber laser which can emit short pulses at high repetition rates is one of the most attractive sources for realizing ultrahigh speed optical communications. This paper reviews femtosecond pulse generation from passively mode-locked fiber lasers. The fundamental characteristics and stabilization mechanisms of an actively mode-locked fiber laser are discussed. Lasing characteristics of the regeneratively mode-locked fiber in AM and FM operation are described.
The second and third order dispersion compensation of picosecond pulses achieved by combining two nonlinearly chirped fiber Bragg gratings Peer-reviewed

T. Imai, T. Komukai, M. Nakazawa

OFC/IOOC 1999 - Optical Fiber Communication Conference and the International Conference on Integrated Optics and Optical Fiber Communication　4　17-19　1999
Publisher: Institute of Electrical and Electronics Engineers Inc.
DOI： 10.1109/OFC.1999.765981 　
40 Gbit/s soliton transmission field experiment over 1,020 km and its extension to 1,360 km using in-line synchronous modulation Peer-reviewed

A. Sahara, K. Suzuki, H. Kubota, T. Komukai, E. Yamada, T. Imai, K. Tamura, M. Nakazawa

OFC/IOOC 1999 - Optical Fiber Communication Conference and the International Conference on Integrated Optics and Optical Fiber Communication　3　112-114　1999
Publisher: Institute of Electrical and Electronics Engineers Inc.
DOI： 10.1109/OFC.1999.768079 　
Ultra high speed soliton transmission in the presence of polarization mode dispersion using in-line synchronous modulation Peer-reviewed

A. Sahara, H. Kubota, M. Nakazawa

OFC/IOOC 1999 - Optical Fiber Communication Conference and the International Conference on Integrated Optics and Optical Fiber Communication　2　38-40　1999
Publisher: Institute of Electrical and Electronics Engineers Inc.
DOI： 10.1109/OFC.1999.766324 　
Toward terabit/s single-channel transmission Invited Peer-reviewed

M. Nakazawa

OFC/IOOC 1999 - Optical Fiber Communication Conference and the International Conference on Integrated Optics and Optical Fiber Communication　4　132-134　1999
Publisher: Institute of Electrical and Electronics Engineers Inc.
DOI： 10.1109/OFC.1999.766017 　
Coherence degradation of a high-order optical soliton train in the presence of noise Peer-reviewed

H Kubota, KR Tamura, M Nakazawa

OPTICAL AMPLIFIERS AND THEIR APPLICATIONS　30　364-367　1999

ISSN： 1094-5695
Handling noise in soliton systems for ultrahigh speed transmission over unlimited distances Invited Peer-reviewed

M Nakazawa

OPTICAL AMPLIFIERS AND THEIR APPLICATIONS　30　41-44　1999

ISSN： 1094-5695
Second- and third-order dispersion compensation of picosecond pulses achieved by combining two nonlinearly chirped fibre Bragg gratings Peer-reviewed

T Imai, T Komukai, M Nakazawa

ELECTRONICS LETTERS　34　(25)　2422-2423　1998/12

DOI： 10.1049/el:19981619 　

ISSN： 0013-5194
Single channel 40Gbit/s soliton transmission field experiment over 1000km in Tokyo metropolitan optical loop network using dispersion compensation Peer-reviewed

A Sahara, K Suzuki, H Kubota, T Komukai, E Yamada, T Imai, K Tamura, M Nakazawa

ELECTRONICS LETTERS　34　(22)　2154-2155　1998/10

DOI： 10.1049/el:19981454 　

ISSN： 0013-5194
40Gbit/s soliton transmission field experiment over 1360km using in-line soliton control Peer-reviewed

K Suzuki, H Kubota, T Komukai, E Yamada, T Imai, K Tamura, A Sahara, M Nakazawa

ELECTRONICS LETTERS　34　(22)　2143-2145　1998/10

DOI： 10.1049/el:19981472 　

ISSN： 0013-5194
Wavelength tunable 1.0ps pulse generation in 1.530-1.555 mu m region from PLL, regeneratively modelocked fibre laser Peer-reviewed

E Yoshida, M Nakazawa

ELECTRONICS LETTERS　34　(18)　1753-1754　1998/09

DOI： 10.1049/el:19981262 　

ISSN： 0013-5194
Timing jitter of solitons compressed in dispersion-decreasing fibers Peer-reviewed

K Tamura, M Nakazawa

OPTICS LETTERS　23　(17)　1360-1362　1998/09

ISSN： 0146-9592
Fabrication of non-linearly chirped fiber Bragg gratings for higher-order dispersion compensation Peer-reviewed

T Komukai, M Nakazawa

OPTICS COMMUNICATIONS　154　(1-3)　5-8　1998/08

DOI： 10.1016/S0030-4018(98)00324-1 　

ISSN： 0030-4018
Mode-locked fiber lasers for optical communications(招待講演) Invited Peer-reviewed

K. Tamura, E. Yoshida, M. Nakazawa

OECC'98　16C1-1　1998/08
Time-domain ABCD matrix formalism for laser mode-locking and optical pulse transmission Peer-reviewed

M Nakazawa, H Kubota, A Sahara, K Tamura

IEEE JOURNAL OF QUANTUM ELECTRONICS　34　(7)　1075-1081　1998/07

DOI： 10.1109/3.687847 　

ISSN： 0018-9197

eISSN： 1558-1713
Dispersion tuning of a linearly chirped fiber Bragg grating without a center wavelength shift by applying a strain gradient Peer-reviewed

T Imai, T Komukai, M Nakazawa

IEEE PHOTONICS TECHNOLOGY LETTERS　10　(6)　845-847　1998/06

DOI： 10.1109/68.681505 　

ISSN： 1041-1135
Long-phase error-free fiber Bragg gratings Peer-reviewed

T Komukai, M Nakazawa

IEEE PHOTONICS TECHNOLOGY LETTERS　10　(5)　687-689　1998/05

DOI： 10.1109/68.669251 　

ISSN： 1041-1135

eISSN： 1941-0174
Ultrafast nonlinear optical loop mirror for demultiplexing 640Gbit/s TDM signals Peer-reviewed

T Yamamoto, E Yoshida, M Nakazawa

ELECTRONICS LETTERS　34　(10)　1013-1014　1998/05

DOI： 10.1049/el:19980712 　

ISSN： 0013-5194
320Gbit/s TDM transmission over 120 km using 400fs pulse train Peer-reviewed

E Yoshida, T Yamamoto, A Sahara, M Nakazawa

ELECTRONICS LETTERS　34　(10)　1004-1005　1998/05

DOI： 10.1049/el:19980728 　

ISSN： 0013-5194
TDM single channel 640Gbit/s transmission experiment over 60km using 400fs pulse train and walk-off free, dispersion flattened nonlinear optical loop mirror Peer-reviewed

M Nakazawa, E Yoshida, T Yamamoto, E Yamada, A Sahara

ELECTRONICS LETTERS　34　(9)　907-908　1998/04

DOI： 10.1049/el:19980590 　

ISSN： 0013-5194
Coherence degradation in the process of supercontinuum generation in an optical fiber Peer-reviewed

M Nakazawa, K Tamura, H Kubota, E Yoshida

OPTICAL FIBER TECHNOLOGY　4　(2)　215-223　1998/04

ISSN： 1068-5200
Ultrafast fiber lasers and their applications to optical communication(招待講演) Invited Peer-reviewed

M. Nakazawa

International Workshop on Current Topics of Laser Technology　17-18　1998/03
Forced phase modulation and self phase modulation effects in dispersion-tuned mode-locked fiber lasers Peer-reviewed

K Tamura, E Yoshida, M Nakazawa

IEICE TRANSACTIONS ON ELECTRONICS　E81C　(2)　195-200　1998/02

ISSN： 0916-8524

eISSN： 1745-1353
Intracavity dispersion effects of a regeneratively and harmonically FM mode-locked erbium-doped fiber laser Peer-reviewed

E Yoshida, K Tamura, M Nakazawa

IEICE TRANSACTIONS ON ELECTRONICS　E81C　(2)　189-194　1998/02

ISSN： 0916-8524

eISSN： 1745-1353
Fabrication of nonlinearly chirped fiber Bragg gratings for high order dispersion compensation Peer-reviewed

T. Komukai, M. Nakazawa

OFC'98　TuM2　1998/02
40 Gbit/s single-channel optical soliton transmission over 70,000 km using in-line synchronous modulation Peer-reviewed

K. Suzuki, H. Kubota, A. Sahara, M. Nakazawa

OFC'98　34　(98)　ThI4-100　1998/02
TDM single channel 640 Gbit/s transmission experiment over 60 km using a 400 fs pulse train and a walk-off free, dispersion-flattened nonlinear optical loop mirror Peer-reviewed

M. Nakazawa, E. Yoshida, T. Yamamoto, E. Yamada, A. Sahara

OFC'98　2　PD14　1998/02
Experiment and analyses of 20-Gbit/s soliton transmission systems using installed optical fiber cable Peer-reviewed

A Sahara, H Kubota, M Nakazawa

ELECTRONICS AND COMMUNICATIONS IN JAPAN PART II-ELECTRONICS　81　(1)　74-83　1998/01

ISSN： 8756-663X
Superb characteristics of dispersion-allocated soliton transmission in TDM and WDM systems Invited Peer-reviewed

M Nakazawa, H Kubota, K Suzuki, E Yamada, A Sahara

NEW TRENDS IN OPTICAL SOLITON TRANSMISSION SYSTEMS　5　197-224　1998
160Gbit/s WDM (20Gbit/s x 8 channels) soliton transmission over 10000km using in-line synchronous modulation and optical filtering Peer-reviewed

M Nakazawa, K Suzuki, H Kubota, A Sahara, E Yamada

ELECTRONICS LETTERS　34　(1)　103-104　1998/01

DOI： 10.1049/el:19980100 　

ISSN： 0013-5194
40Gbit/s single channel optical soliton transmission over 70000km using in-line synchronous modulation and optical filtering Peer-reviewed

K Suzuki, H Kubota, A Sahara, M Nakazawa

ELECTRONICS LETTERS　34　(1)　98-100　1998/01

DOI： 10.1049/el:19980063 　

ISSN： 0013-5194
Efficient optical pulse compression with optical gain via four-wave mixing Peer-reviewed

NAKAZAWA Masataka

IEICE of Japan　J81-C-I　(3)　148-157　1998
Publisher: The Institute of Electronics, Information and Communication Engineers
ISSN： 0915-1893
A single-frequency and single-polarization fiber ring laser using a 5 GHz fiber Bragg grating Peer-reviewed

NAKAZAWA Masataka

IEICE of Japan　J81-C-I　(8)　451-459　1998
Publisher: The Institute of Electronics, Information and Communication Engineers
ISSN： 0915-1893
Marked increase in power margin through the use of dispersion-allocated soliton and evaluation of transmission characteristics using Q map: Comparison between D-A soliton, NRZ pulse, and RZ pulse at zero GVD Peer-reviewed

M Nakazawa, A Sahara, H Kubota

ELECTRONICS AND COMMUNICATIONS IN JAPAN PART I-COMMUNICATIONS　80　(12)　17-27　1997/12

ISSN： 8756-6621
Active optical pulse compression with a gain of 29.0 dB by using four-wave mixing in an optical fiber Peer-reviewed

T Yamamoto, M Nakazawa

IEEE PHOTONICS TECHNOLOGY LETTERS　9　(12)　1595-1597　1997/12

DOI： 10.1109/68.643279 　

ISSN： 1041-1135

eISSN： 1941-0174
Advantages of dispersion-allocated soliton transmission and its application to conventional 1.3 μm single-mode fiber(招待講演) Invited Peer-reviewed

H. Kubota, M. Nakazawa

International Symposium NOLTA'98　M3F　1997/12
A wavelength tunable Q-switched fiber laser using fiber Bragg gratings Peer-reviewed

T Imai, T Komukai, T Yamamoto, M Nakazawa

ELECTRONICS AND COMMUNICATIONS IN JAPAN PART II-ELECTRONICS　80　(11)　12-21　1997/11

ISSN： 8756-663X
Demultiplexing and routing of TDM signal using wavelength conversion by four-wave mixing and wavelength routing by fiber gratings Peer-reviewed

T Yamamoto, T Imai, T Komukai, M Nakazawa

ELECTRONICS AND COMMUNICATIONS IN JAPAN PART II-ELECTRONICS　80　(10)　28-36　1997/10

ISSN： 8756-663X
Application of a fiber Bragg grating to spectral filtering Peer-reviewed

T Komukai, T Yamamoto, T Imai, M Nakazawa

ELECTRONICS AND COMMUNICATIONS IN JAPAN PART II-ELECTRONICS　80　(9)　1-9　1997/09

ISSN： 8756-663X
Low-threshold 115-GHz continuous-wave modulational-instability erbium-doped fiber laser Peer-reviewed

E Yoshida, M Nakazawa

OPTICS LETTERS　22　(18)　1409-1411　1997/09

ISSN： 0146-9592

eISSN： 1539-4794
Optimum fiber dispersion for two-step dispersion-allocated optical soliton, RZ at zero GVD and NRZ systems Peer-reviewed

A Sahara, H Kubota, M Nakazawa

IEEE PHOTONICS TECHNOLOGY LETTERS　9　(8)　1179-1181　1997/08

DOI： 10.1109/68.605543 　

ISSN： 1041-1135

eISSN： 1941-0174
Numerical and experimental comparison of soliton, RZ pulse and NRZ pulses under two-step dispersion allocation Peer-reviewed

M Nakazawa, E Yamada, H Kubota, T Yamamoto, A Sahara

ELECTRONICS LETTERS　33　(17)　1480-1482　1997/08

DOI： 10.1049/el:19971001 　

ISSN： 0013-5194
100Gbit/s WDM (20Gbit/s x 5 channels) soliton transmission over 10000km using in-line synchronous modulation and optical filtering Peer-reviewed

M. Nakazawa, K. Suzuki, H. Kubota, A. Sahara, E. Yamada

Electronics Letters　33　(14)　1233-1234　1997/07/03
Publisher: Institution of Engineering and Technology
DOI： 10.1049/el:19970815 　

ISSN： 0013-5194
Femtosecond fiber laser at 10 GHz and its application as a multi-wavelength optical pulse source Peer-reviewed

E Yoshida, K Tamura, E Yamada, M Nakazawa

ELECTRONICS AND COMMUNICATIONS IN JAPAN PART II-ELECTRONICS　80　(7)　56-63　1997/07

ISSN： 8756-663X
100Gbit/s WDM (20Gbit/sx5 channels) soliton transmission over 10000km using in-line synchronous modulation and optical filtering Peer-reviewed

M Nakazawa, K Suzuki, H Kubota, A Sahara, E Yamada

ELECTRONICS LETTERS　33　(14)　1233-1234　1997/07

DOI： 10.1049/el:19970815 　

ISSN： 0013-5194

eISSN： 1350-911X
Ideal phase-locked-loop (PLL) operation of a 10GHz erbium-doped fibre laser using regenerative modelocking as an optical voltage controlled oscillator Peer-reviewed

M Nakazawa, E Yoshida, K Tamura

ELECTRONICS LETTERS　33　(15)　1318-1320　1997/07

DOI： 10.1049/el:19970902 　

ISSN： 0013-5194

eISSN： 1350-911X
An efficient 0.04-nm apodized fiber Bragg grating and its application to narrow-band spectral filtering Peer-reviewed

T Komukai, K Tamura, M Nakazawa

IEEE PHOTONICS TECHNOLOGY LETTERS　9　(7)　934-936　1997/07

DOI： 10.1109/68.593356 　

ISSN： 1041-1135

eISSN： 1941-0174
Optical soliton and nonlinear transmission systems(招待講演) Invited Peer-reviewed

M. Nakazawa

OECC'97(OptoElectronics and Communication Conference'97)　PA3-1　1997/07
Low Threshold, 115 GHz continuous wave modulational instability erbium-doped fiber laser Peer-reviewed

E. Yoshida, M. Nakazawa

OECC'97(OptoElectronics and Communication Conference'97)　PDP2-1　1997/07
Generation and transmission of optical soliton pulses Peer-reviewed

M Nakazawa, H Kubota, E Yamada

ELECTRONICS AND COMMUNICATIONS IN JAPAN PART II-ELECTRONICS　80　(4)　53-66　1997/04

ISSN： 8756-663X
Fabrication and wavelength tuning of a high-quality fiber Bragg grating Peer-reviewed

T Komukai, T Yamamoto, T Imai, M Nakazawa

ELECTRONICS AND COMMUNICATIONS IN JAPAN PART II-ELECTRONICS　80　(4)　27-34　1997/04

ISSN： 8756-663X
Highly efficient four-wave mixing in an optical fiber with intensity dependent phase matching Peer-reviewed

T Yamamoto, M Nakazawa

IEEE PHOTONICS TECHNOLOGY LETTERS　9　(3)　327-329　1997/03

DOI： 10.1109/68.556062 　

ISSN： 1041-1135

eISSN： 1941-0174
10Gbit/s, 10600km, dispersion-allocated soliton transmission using conventional 1.3 mu m singlemode fibres Peer-reviewed

E Yamada, H Kubota, T Yamamoto, A Sahara, M Nakazawa

ELECTRONICS LETTERS　33　(7)　602-603　1997/03

DOI： 10.1049/el:19970414 　

ISSN： 0013-5194

eISSN： 1350-911X
Dispersion-allocated soliton technology and the stretched-pulse mode-locked fiber laser(招待講演) Invited Peer-reviewed

M. Nakazawa

OFC'97(Conference on Optical Fiber Communication)　1997/02
100 Gbit/s(20 Gbit/sx5 channels)soliton transmission over 10,000 km using in-line synchronous modulation and optical filtering Peer-reviewed

M. Nakazawa, K. Suzuki, H. Kubota, A. Sahara, E. Yamada

OFC'97　PDP21　1997/02
Numerical and experimental comparison between the dispersion-allocated soliton, RZ and NRZ pulses at zero group velocity dispersion Peer-reviewed

E Yamada, H Kubota, T Yamamoto, A Sahara, M Nakazawa

IOOC-ECOC 97 - 11TH INTERNATIONAL CONFERENCE ON INTEGRATED OPTICS AND OPTICAL FIBRE COMMUNICATIONS / 23RD EUROPEAN CONFERENCE ON OPTICAL COMMUNICATIONS, VOL 3　(448)　327-330　1997

ISSN： 0537-9989
Application of fiber Bragg gratings to spectral filtering Peer-reviewed

NAKAZAWA Masataka

IEICE of Japan　J80-C-I　32-40　1997
Optical cable amplifier Peer-reviewed

NAKAZAWA Masataka

The Laser Society of Japan, Rev. of Laser Eng.　25　121-125　1997
Femtosecond fiber laser at 10 GHz and its application as a multi-wavelength optical pulse source Peer-reviewed

NAKAZAWA Masataka

IEICE of Japan　J80-C-I　(2)　70-77　1997
Publisher: The Institute of Electronics, Information and Communication Engineers
ISSN： 0915-1893
Marked increase in the power margin through the use of dispersion-allocated soliton and evaluation of transmission characteristics using Q mapping-Comparison between D-A soliton, NRZ pulse and RZ pulse at zero GVD- Peer-reviewed

NAKAZAWA Masataka

IEICE of Japan　J80-B-I　(3)　148-158　1997
Publisher: The Institute of Electronics, Information and Communication Engineers
ISSN： 0915-1877
Demutliplexing and routing of TDM signal using wavelength conversion by fiber four-wave mixing and wavelength routing by fiber gratings Peer-reviewed

NAKAZAWA Masataka

IEICE of Japan　J80-C-I　(5)　186-194　1997
Publisher: The Institute of Electronics, Information and Communication Engineers
ISSN： 0915-1893
Wavelength tunable Q-switched fiber laser using fiber Bragg gratings Peer-reviewed

NAKAZAWA Masataka

IEICE of Japan　J80-C-I　(5)　195-203　1997
Publisher: The Institute of Electronics, Information and Communication Engineers
ISSN： 0915-1893
Experiments and analyses of 20 Gbit/s soliton transmission systems using installed optical fiber cables Peer-reviewed

NAKAZAWA Masataka

IEICE of Japan　J80-C-I　(5)　204-212　1997
Publisher: The Institute of Electronics, Information and Communication Engineers
ISSN： 0915-1893
Advantages of dispersion-allocated soliton by comparison with conventional NRZ and RZ pulse transmission at zero GVD Peer-reviewed

NAKAZAWA Masataka

TOPS, OSA　12　299-304　1997
Recent progress in optical soliton communication and its future prospects-Analogy between optical pulse transmission and laser mode-locking Peer-reviewed

NAKAZAWA Masataka

Journal of Applied Physics　66　(9)　922-932　1997
Publisher: The Japan Society of Applied Physics
DOI： 10.11470/oubutsu1932.66.922 　

ISSN： 0369-8009
Dispersion-tuned harmonically mode-locked fiber ring laser for self-synchronization to an external clock Peer-reviewed

K Tamura, M Nakazawa

OPTICS LETTERS　21　(24)　1984-1986　1996/12

DOI： 10.1364/OL.21.001984 　

ISSN： 0146-9592

eISSN： 1539-4794
Pulse energy equalization in harmonically FM mode-locked losers with slow gain Peer-reviewed

K Tamura, M Nakazawa

OPTICS LETTERS　21　(23)　1930-1932　1996/12

DOI： 10.1364/OL.21.001930 　

ISSN： 0146-9592

eISSN： 1539-4794
Recent progress in optical soliton communication(招待講演) Invited Peer-reviewed

M. Nakazawa

International Symposium on Solitons　1996/12
Fabrication of high-quality long-fiber Bragg grating by monitoring 3.1-eV radiation (400 nm) from GeO defects Peer-reviewed

T Komukai, M Nakazawa

IEEE PHOTONICS TECHNOLOGY LETTERS　8　(11)　1495-1497　1996/11

DOI： 10.1109/68.541561 　

ISSN： 1041-1135

eISSN： 1941-0174
Ultra-high speed mode-locked fiber lasers in the pico-femtosecond region(招待講演) Invited Peer-reviewed

E. Yoshida, M. Nakazawa

ROSC'96　1996/11
A wavelength tunable Q-switched erbium-doped fiber laser with fiber Bragg grating mirrors Peer-reviewed

T Imai, T Komukai, T Yamamoto, M Nakazawa

JAPANESE JOURNAL OF APPLIED PHYSICS PART 2-LETTERS & EXPRESS LETTERS　35　(10A)　L1275-L1277　1996/10

DOI： 10.1143/jjap.35.L1275 　

ISSN： 0021-4922
Optimization of power extraction in a high-power soliton fiber ring laser containing a chirped fiber grating Peer-reviewed

K Tamura, T Komukai, M Nakazawa

APPLIED PHYSICS LETTERS　69　(11)　1535-1537　1996/09

DOI： 10.1063/1.117996 　

ISSN： 0003-6951

eISSN： 1077-3118
Generation of 10GHz pulse trains at 16 wavelengths by spectrally slicing a high power femtosecond source Peer-reviewed

K Tamura, E Yoshida, M Nakazawa

ELECTRONICS LETTERS　32　(18)　1691-1693　1996/08

DOI： 10.1049/el:19961119 　

ISSN： 0013-5194

eISSN： 1350-911X
60Gbit/s WDM (20 Gbit/s x 3 unequally spaced channels) soliton transmission over 10000 km using in-line synchronous modulation and optical filtering Peer-reviewed

M Nakazawa, K Suzuki, H Kubota, E Yamada

ELECTRONICS LETTERS　32　(18)　1686-1688　1996/08

DOI： 10.1049/el:19961152 　

ISSN： 0013-5194

eISSN： 1350-911X
Marked increase in the power margin through the use of a dispersion-allocated soliton Peer-reviewed

M Nakazawa, H Kubota, A Sahara, K Tamura

IEEE PHOTONICS TECHNOLOGY LETTERS　8　(8)　1088-1090　1996/08

DOI： 10.1109/68.508747 　

ISSN： 1041-1135

eISSN： 1941-0174
Dispersion-allocated soliton transmission(招待講演) Invited Peer-reviewed

M. Nakazawa, H. Kubota, A. Sahara

2nd International Workshop for Soliton Communication　1996/08
80-200GHz erbium doped fibre laser using a rational harmonic mode-locking technique Peer-reviewed

E. Yoshida, M. Nakazawa

Electronics Letters　32　(15)　1370-1372　1996/07/18
Publisher: Institution of Engineering and Technology
DOI： 10.1049/el:19960896 　

ISSN： 0013-5194
10GHz, 2ps regeneratively and harmonically FM mode-locked erbium fibre ring laser Peer-reviewed

M Nakazawa, E Yoshida, K Tamura

ELECTRONICS LETTERS　32　(14)　1285-1287　1996/07

DOI： 10.1049/el:19960838 　

ISSN： 0013-5194

eISSN： 1350-911X
Direct generation of a 750fs, 10GHz pulse train from a regeneratively mode-locked fibre laser with multiple harmonic modulation Peer-reviewed

M Nakazawa, E Yoshida

ELECTRONICS LETTERS　32　(14)　1291-1293　1996/07

DOI： 10.1049/el:19960825 　

ISSN： 0013-5194

eISSN： 1350-911X
80 similar to 200GHz erbium doped fibre laser using a rational harmonic mode-locking technique Peer-reviewed

E Yoshida, M Nakazawa

ELECTRONICS LETTERS　32　(15)　1370-1372　1996/07

DOI： 10.1049/el:19960896 　

ISSN： 0013-5194

eISSN： 1350-911X
A repetition-rate stabilized and tunable, regeneratively mode-locked fiber laser using an offset-locking technique Peer-reviewed

M Nakazawa, E Yoshida, E Yamada, Y Kimura

JAPANESE JOURNAL OF APPLIED PHYSICS PART 2-LETTERS & EXPRESS LETTERS　35　(6A)　L691-L694　1996/06

DOI： 10.1143/JJAP.35.L691 　

ISSN： 0021-4922
NOLM oscillator and its injection locking technique for timing clock extraction and demultiplexing Peer-reviewed

M Nakazawa, K Suzuki, E Yamada

ELECTRONICS LETTERS　32　(12)　1122-1123　1996/06

DOI： 10.1049/el:19960749 　

ISSN： 0013-5194

eISSN： 1350-911X
Q-factor contour mapping for evaluation of optical transmission systems: Soliton against NRZ against RZ pulse at zero group velocity dispersion Peer-reviewed

A Sahara, H Kubota, M Nakazawa

ELECTRONICS LETTERS　32　(10)　915-916　1996/05

DOI： 10.1049/el:19960590 　

ISSN： 0013-5194

eISSN： 1350-911X
40 Gbit/s WDM (10Gbit/sx4 unequally spaced channels) soliton transmission over 10000 km using synchronous modulation and narrow band optical filtering Peer-reviewed

M Nakazawa, K Suzuki, H Kubota, Y Kimura, E Yamada, K Tamura, T Komukai, T Imai

ELECTRONICS LETTERS　32　(9)　828-830　1996/04

DOI： 10.1049/el:19960543 　

ISSN： 0013-5194

eISSN： 1350-911X
Generation of a 0.5 W average power train of femtosecond pulses at 10 GHz in the 1.55 mu m region Peer-reviewed

K Tamura, E Yoshida, E Yamada, M Nakazawa

ELECTRONICS LETTERS　32　(9)　835-836　1996/04

DOI： 10.1049/el:19960528 　

ISSN： 0013-5194

eISSN： 1350-911X
Soliton transmission field experiment Peer-reviewed

H Kubota, M Nakazawa

NTT REVIEW　8　(2)　65-71　1996/03

ISSN： 0915-2334
Nonlinear pulse transmission through an optical fiber at zero-average group velocity dispersion Peer-reviewed

M Nakazawa, H Kubota, K Tamura

IEEE PHOTONICS TECHNOLOGY LETTERS　8　(3)　452-454　1996/03

DOI： 10.1109/68.481147 　

ISSN： 1041-1135

eISSN： 1941-0174
Telecommunications rides a new wave Peer-reviewed

M Nakazawa

PHOTONICS SPECTRA　30　(2)　97-+　1996/02

ISSN： 0731-1230
Supermode noise suppression in a harmonically modelocked fibre laser by selfphase modulation and spectral filtering Peer-reviewed

M Nakazawa, K Tamura, E Yoshida

ELECTRONICS LETTERS　32　(5)　461-463　1996/02

DOI： 10.1049/el:19960318 　

ISSN： 0013-5194

eISSN： 1350-911X
Optical soliton transmission technology

Nakazawa Masataka

rle　24　283-287　1996
Publisher: The Laser Society of Japan
DOI： 10.2184/lsj.24.Supplement_283 　

ISSN： 0387-0200
A dispersion-allocated soliton and its impact on soliton communication Invited Peer-reviewed

H Kubota, M Nakazawa

PHYSICS AND APPLICATIONS OF OPTICAL SOLITONS IN FIBRES '95　3　27-36　1996
Pulse compression by nonlinear pulse evolution with reduced optical wave breaking in erbium-doped fiber amplifiers Peer-reviewed

K Tamura, M Nakazawa

OPTICS LETTERS　21　(1)　68-70　1996/01

DOI： 10.1364/OL.21.000068 　

ISSN： 0146-9592

eISSN： 1539-4794
Recent progress in ultra-high speed optical soliton communication Peer-reviewed

NAKAZAWA Masataka

IEICE of Japan　79　259-271　1996
Recent progress in long-distance soliton communication Peer-reviewed

NAKAZAWA Masataka

Laser Society of Japan, Rev. of Laser Eng.　24　(6)　633-640　1996
Publisher: The Laser Society of Japan
DOI： 10.2184/lsj.24.633 　

ISSN： 0387-0200

More details Close

Current progress on long-distance soliton transmission technologies is summarized, in which the use of erbium-doped fiber amplifiers has been a major breakthrough for the soliton communication. Techniques which can send solitons over unlimited distance are described, in which soliton control in time and frequency domains plays an important role as an optical 3R repeater. Finally, a new soliton transmission technique which employs dispersion allocation is described, which enables us to bring the soliton transmission into a developmental stage.
Generation and transmission of optical soliton pulses Peer-reviewed

NAKAZAWA Masataka

IEICE of Japan　J79-C-I　265-277　1996
Fabrication of high quality fiber Bragg grating and its wavelength tuning Peer-reviewed

NAKAZAWA Masataka

IEICE of Japan　J79-C-1　(11)　413-419　1996
Publisher: The Institute of Electronics, Information and Communication Engineers
ISSN： 0915-1893
60Gbit/s WDM (20Gbit/s × 3 unequally spaced channels) soliton transmission over 10000km using in-line synchronous modulation and optical filtering Peer-reviewed

M. Nakazawa, K. Suzuki, H. Kubota, E. Yamada

Electronics Letters　32　(18)　1686-1688　1996
Publisher: Institution of Engineering and Technology
DOI： 10.1049/el:19961152 　

ISSN： 0013-5194
60Gbit/s WDM (20Gbit/s × 3 unequally spaced channels) soliton transmission over 10000km using in-line synchronous modulation and optical filtering Invited Peer-reviewed

M. Nakazawa, K. Suzuki, H. Kubota, E. Yamada

Electronics Letters　32　(18)　1686-1688　1996
Publisher: Institution of Engineering and Technology
DOI： 10.1049/el:19961152 　

ISSN： 0013-5194
Ultrahigh speed picosecond-femtosecond fiber lasers Peer-reviewed

E Yoshida, Y Kimura, M Nakazawa

OPTOELECTRONICS-DEVICES AND TECHNOLOGIES　10　(4)　531-542　1995/12

ISSN： 0912-5434
Optimizing power extraction in stretched-pulse fiber ring lasers Peer-reviewed

K Tamura, M Nakazawa

APPLIED PHYSICS LETTERS　67　(25)　3691-3693　1995/12

DOI： 10.1063/1.115351 　

ISSN： 0003-6951

eISSN： 1077-3118
High energy, sub-picosecond pulse compression at 10GHz using a fibre fibre-grating pulse compressor Peer-reviewed

K Tamura, T Komukai, T Yamamoto, T Imai, E Yoshida, M Nakazawa

ELECTRONICS LETTERS　31　(25)　2194-2195　1995/12

DOI： 10.1049/el:19951472 　

ISSN： 0013-5194

eISSN： 1350-911X
80-160 Gbit/s ultrahigh Speed Soliton Transmission and Related Soliton Technology(招待講演) Invited Peer-reviewed

K. Suzuki, M. Nakazawa

20th Australian Conference on Optical Fibre Technology, ACOFT'95　347-350　1995/12
Recent progress in soliton communication(招待講演) Invited Peer-reviewed

H. Kubota, M. Nakazawa

International Symposium on Nonlinear Theory and its Application, NOLTA'95　G-4　1995/12
HIGH-SPEED OPTICAL-PATH ROUTING BY USING 4-WAVE-MIXING AND A WAVELENGTH ROUTER WITH FIBER GRATINGS AND OPTICAL CIRCULATORS Peer-reviewed

T YAMAMOTO, T IMAI, T KOMUKAI, Y MIYAJIMA, M NAKAZAWA

OPTICS COMMUNICATIONS　120　(5-6)　245-248　1995/11

DOI： 10.1016/0030-4018(95)00436-C 　

ISSN： 0030-4018
Recent progress in femtosecond fiber lasers(招待講演) Invited Peer-reviewed

E. Yoshida, M. Nakazawa

9th international symposium on ultrafast processes in spectroscopy, UPS'95　MC3　1995/11
EFFICIENT FIBER GRATINGS FORMED ON HIGH NA DISPERSION-SHIFTED FIBER AND DISPERSION-FLATTENED FIBER Peer-reviewed

T KOMUKAI, M NAKAZAWA

JAPANESE JOURNAL OF APPLIED PHYSICS PART 2-LETTERS & EXPRESS LETTERS　34　(10A)　L1286-L1287　1995/10

DOI： 10.1143/jjap.34.L1286 　

ISSN： 0021-4922
OPTICAL CABLE AMPLIFIERS Peer-reviewed

M NAKAZAWA, Y KIMURA

ELECTRONICS LETTERS　31　(20)　1744-1745　1995/09

DOI： 10.1049/el:19951173 　

ISSN： 0013-5194

eISSN： 1350-911X
A NOVEL TECHNIQUE FOR MEASURING GROUP-VELOCITY DISPERSION OF AN INSTALLED ULTRALONG FIBER BY USING ERBIUM-DOPED FIBER AMPLIFIERS Peer-reviewed

M NAKAZAWA, A SAHARA, T IMAI, T YAMAMOTO, E YAMADA, Y KIMURA

JAPANESE JOURNAL OF APPLIED PHYSICS PART 2-LETTERS & EXPRESS LETTERS　34　(9A)　L1167-L1169　1995/09

DOI： 10.1143/jjap.34.L1167 　

ISSN： 0021-4922
BROAD-BAND LIGHT GENERATION BY FEMTOSECOND PULSE AMPLIFICATION WITH STIMULATED RAMAN-SCATTERING IN A HIGH-POWER ERBIUM-DOPED FIBER AMPLIFIER Peer-reviewed

K TAMURA, E YOSHIDA, T SUGAWA, M NAKAZAWA

OPTICS LETTERS　20　(15)　1631-1633　1995/08

ISSN： 0146-9592

eISSN： 1539-4794
GENERATION OF TERABIT PER SECOND OPTICAL-DATA PULSE-TRAIN Peer-reviewed

E YAMADA, E YOSHIDA, T KITOH, M NAKAZAWA

ELECTRONICS LETTERS　31　(16)　1342-1344　1995/08

DOI： 10.1049/el:19950922 　

ISSN： 0013-5194

eISSN： 1350-911X
SOLITON TRANSMISSION AT 20 GBIT/S OVER 2000 KM IN TOKYO METROPOLITAN OPTICAL NETWORK Peer-reviewed

M NAKAZAWA, Y KIMURA, K SUZUKI, H KUBOTA, T KOMUKAI, E YAMADA, T SUGAWA, E YOSHIDA, T YAMAMOTO, T IMAI, A SAHARA, O YAMAUCHI, M UMEZAWA

ELECTRONICS LETTERS　31　(17)　1478-1479　1995/08

DOI： 10.1049/el:19950967 　

ISSN： 0013-5194

eISSN： 1350-911X
POLARIZATION DEPENDENCE OF FEMTOSECOND SOLITON-SOLITON INTERACTIONS IN DISPERSION-SHIFTED FIBER Peer-reviewed

T SUGAWA, H KUBOTA, M NAKAZAWA

OPTICS LETTERS　20　(13)　1453-1455　1995/07

ISSN： 0146-9592

eISSN： 1539-4794
ANALYSES OF THE DISPERSION-ALLOCATED BRIGHT AND DARK SOLITONS Peer-reviewed

M NAKAZAWA, H KUBOTA

JAPANESE JOURNAL OF APPLIED PHYSICS PART 2-LETTERS & EXPRESS LETTERS　34　(7B)　L889-L891　1995/07

DOI： 10.1143/jjap.34.L889 　

ISSN： 0021-4922
FIELD DEMONSTRATION OF SOLITON TRANSMISSION AT 10GBIT/S OVER 2000KM IN TOKYO METROPOLITAN OPTICAL LOOP NETWORK Peer-reviewed

M NAKAZAWA, Y KIMURA, K SUZUKI, H KUBOTA, T KOMUKAI, E YAMADA, T SUGAWA, E YOSHIDA, T YAMAMOTO, T IMAI, A SAHARA, H NAKAZAWA, O YAMAUCHI, M UMEZAWA

ELECTRONICS LETTERS　31　(12)　992-994　1995/06

DOI： 10.1049/el:19950680 　

ISSN： 0013-5194

eISSN： 1350-911X
CONSTRUCTION OF A DISPERSION-ALLOCATED SOLITON TRANSMISSION-LINE USING CONVENTIONAL DISPERSION-SHIFTED NONSOLITON FIBERS Peer-reviewed

M NAKAZAWA, H KUBOTA

JAPANESE JOURNAL OF APPLIED PHYSICS PART 2-LETTERS & EXPRESS LETTERS　34　(6A)　L681-L683　1995/06

DOI： 10.1143/jjap.34.L681 　

ISSN： 0021-4922
FEMTOSECOND PULSE GENERATION OVER 82NM WAVELENGTH SPAN FROM PASSIVELY MODELOCKED ERBIUM-DOPED FIBER LASER Peer-reviewed

K TAMURA, Y KIMURA, M NAKAZAWA

ELECTRONICS LETTERS　31　(13)　1062-1063　1995/06

DOI： 10.1049/el:19950709 　

ISSN： 0013-5194

eISSN： 1350-911X
10GBIT/S PSEUDORANDOM DARK SOLITON DATA-TRANSMISSION OVER 1200KM Peer-reviewed

M NAKAZAWA, K SUZUKI

ELECTRONICS LETTERS　31　(13)　1076-1077　1995/06

DOI： 10.1049/el:19950701 　

ISSN： 0013-5194

eISSN： 1350-911X
GENERATION OF A PSEUDORANDOM DARK SOLITON DATA TRAIN AND ITS COHERENT DETECTION BY ONE-BIT-SHIFTING WITH A MACH-ZEHNDER INTERFEROMETER Peer-reviewed

M NAKAZAWA, K SUZUKI

ELECTRONICS LETTERS　31　(13)　1084-1085　1995/06

DOI： 10.1049/el:19950700 　

ISSN： 0013-5194

eISSN： 1350-911X
TUNABLE SINGLE-FREQUENCY ERBIUM-DOPED FIBER RING LASERS USING FIBER GRATING ETALONS Peer-reviewed

T KOMUKAI, M NAKAZAWA

JAPANESE JOURNAL OF APPLIED PHYSICS PART 2-LETTERS & EXPRESS LETTERS　34　(6A)　L679-L680　1995/06

DOI： 10.1143/jjap.34.L679 　

ISSN： 0021-4922
Ultrahigh Speed optical soliton communication and related technology(招待講演) Invited Peer-reviewed

M. Nakazawa

10th International Conference on Integrated Optics and Optical Fibre Communication, IOOC'95　FD2-1　1995/06
Optical demultiplexing and routing of TDM signal by using four-wave mixing and a novel wavelength router with optical circulators and fiber gratings Peer-reviewed

T. Yamamoto, T. Imai, T. Komukai, Y. Miyajima, M. Nakazawa

10th International Conference on Integrated Optics and Optical Fibre Communication, IOOC'95　WB3-2　1995/06
Generation of femtosecond pulse train at 20 GHz using an erbium-doped fibre laser and a dispersion-decreasing erbium-doped fibre amplifier Peer-reviewed

E. Yoshida, Y. Kimura, M. Nakazawa

10th International Conference on Integrated Optics and Optical Fibre Communication, IOOC'95　ThA1-1　1995/06
FIELD DEMONSTRATION OF SOLITON TRANSMISSION AT 10GBIT/S OVER 2000KM IN TOKYO METROPOLITAN OPTICAL LOOP NETWORK Peer-reviewed

M NAKAZAWA, Y KIMURA, K SUZUKI, H KUBOTA, T KOMUKAI, E YAMADA, T SUGAWA, E YOSHIDA, T YAMAMOTO, T IMAI, A SAHARA, H NAKAZAWA, O YAMAUCHI, M UMEZAWA

ELECTRONICS LETTERS　31　(12)　992-994　1995/06

ISSN： 0013-5194

eISSN： 1350-911X
10 Gb/s pseudorandom dark soliton transmission over 1200 km using new coding and detection schemes with supression of stimulated Brillouin scattering Peer-reviewed

M. Nakazawa, K. Suzuki

10th International Conference on Integrated Optics and Optical Fibre Communication, IOOC'95　PD2-2　1995/06
Optical demultiplexing and routing of a TDM signal by using four-wave mixing and a novel wavelength router with optical circulators and fibre gratings Invited Peer-reviewed

T. Yamamoto, T. Imai, T. Komukai, Y. Miyajima, M. Nakazawa

Electronics Letters　31　(9)　744-745　1995/04/27

DOI： 10.1049/el:19950479 　

ISSN： 0013-5194
OPTICAL DEMULTIPLEXING AND ROUTING OF A TDM SIGNAL BY USING 4-WAVE-MIXING AND A NOVEL WAVELENGTH ROUTER WITH OPTICAL CIRCULATORS AND FIBER GRATINGS Peer-reviewed

T YAMAMOTO, T IMAI, T KOMUKAI, Y MIYAJIMA, M NAKAZAWA

ELECTRONICS LETTERS　31　(9)　744-745　1995/04

DOI： 10.1049/el:19950479 　

ISSN： 0013-5194

eISSN： 1350-911X
IN-LINE FIBER GRATING-TYPE OPTICAL BANDPASS FILTER TUNED BY APPLYING LATERAL STRESS Peer-reviewed

T KOMUKAI, Y MIYAJIMA, M NAKAZAWA

JAPANESE JOURNAL OF APPLIED PHYSICS PART 2-LETTERS & EXPRESS LETTERS　34　(3A)　L306-L308　1995/03

DOI： 10.1143/jjap.34.L306 　

ISSN： 0021-4922
20GHZ, 1.8PS PULSE GENERATION FROM A REGENERATIVELY MODELOCKED ERBIUM-DOPED FIBER LASER AND ITS FEMTOSECOND PULSE-COMPRESSION Peer-reviewed

E YOSHIDA, Y KIMURA, M NAKAZAWA

ELECTRONICS LETTERS　31　(5)　377-378　1995/03

DOI： 10.1049/el:19950231 　

ISSN： 0013-5194

eISSN： 1350-911X
160GBIT/S SOLITON DATA-TRANSMISSION OVER 200KM Peer-reviewed

M NAKAZAWA, K SUZUKI, E YOSHIDA, E YAMADA, T KITOH, M KAWACHI

ELECTRONICS LETTERS　31　(7)　565-566　1995/03

DOI： 10.1049/el:19950405 　

ISSN： 0013-5194

eISSN： 1350-911X
Polarization dependence of soliton interactions and soliton self-frequency shift in a femtosecond soliton transmission Peer-reviewed

T. Sugawa, K. Kurokawa, H. Kubota, M. Nakazawa

Conference on Optical Fiber Communication, OFC'95　FB1　1995/03
OPTICAL SOLITON COMMUNICATION IN A POSITIVELY AND NEGATIVELY DISPERSION-ALLOCATED OPTICAL-FIBER TRANSMISSION-LINE Peer-reviewed

M NAKAZAWA, H KUBOTA

ELECTRONICS LETTERS　31　(3)　216-217　1995/02

DOI： 10.1049/el:19950159 　

ISSN： 0013-5194

eISSN： 1350-911X
AN IN-LINE OPTICAL BANDPASS FILTER WITH FIBER GRATINGS AND AN OPTICAL CIRCULATOR AND ITS APPLICATION TO PULSE-COMPRESSION Peer-reviewed

T KOMUKAI, Y MIYAJIMA, M NAKAZAWA

JAPANESE JOURNAL OF APPLIED PHYSICS PART 2-LETTERS & EXPRESS LETTERS　34　(2B)　L230-L232　1995/02

DOI： 10.1143/jjap.34.L230 　

ISSN： 0021-4922
SOLITON TRANSMISSION CONTROL FOR ULTRA-HIGH-SPEED SYSTEM Peer-reviewed

H KUBOTA, M NAKAZAWA

IEICE TRANSACTIONS ON ELECTRONICS　E78C　(1)　5-11　1995/01

ISSN： 0916-8524

eISSN： 1745-1353
POLARIZATION DEPENDENCE OF SOLITON-INTERACTIONS IN FEMTOSECOND SOLITON TRANSMISSION Peer-reviewed

T SUGAWA, K KUROKAWA, H KUBOTA, M NAKAZAWA

IEICE TRANSACTIONS ON ELECTRONICS　E78C　(1)　28-37　1995/01

ISSN： 0916-8524

eISSN： 1745-1353
Recent Progress in Optical Soliton Communication Peer-reviewed

Kazunori Suzuki, Masataka Nakazawa

Optical Fiber Technology　1　(4)　289-308　1995

DOI： 10.1006/ofte.1995.1021 　

ISSN： 1068-5200
Efficient fiber gratings formed on high NA dispersion-shifted fibers Peer-reviewed

T Komukai, M Nakazawa

21ST EUROPEAN CONFERENCE ON OPTICAL COMMUNICATION - ECOC '95, VOLS 1-4　31-34　1995
SUBPICOSECOND OPTICAL DEMULTIPLEXING AT 10-GHZ WITH ZERO-DISPERSION, DISPERSION-FLATTENED, NONLINEAR FIBER LOOP MIRROR CONTROLLED BY 500FS GAIN-SWITCHED LASER-DIODE Peer-reviewed

E YAMADA, K SUZUKI, M NAKAZAWA

ELECTRONICS LETTERS　30　(23)　1966-1968　1994/11

DOI： 10.1049/el:19941352 　

ISSN： 0013-5194

eISSN： 1350-911X
SOLITON SELF-FREQUENCY SHIFT IN ORTHOGONALLY POLARIZED FEMTOSECOND SOLITONS Peer-reviewed

T SUGAWA, K KUROKAWA, H KUBOTA, M NAKAZAWA

ELECTRONICS LETTERS　30　(23)　1963-1965　1994/11

DOI： 10.1049/el:19941337 　

ISSN： 0013-5194

eISSN： 1350-911X
GENERATION OF A 170FS, 10GHZ TRANSFORM-LIMITED PULSE-TRAIN AT 1.55-MU-M USING A DISPERSION-DECREASING, ERBIUM-DOPED ACTIVE SOLITON COMPRESSOR Peer-reviewed

M NAKAZAWA, E YOSHIDA, H KUBOTA, Y KIMURA

ELECTRONICS LETTERS　30　(24)　2038-2040　1994/11

DOI： 10.1049/el:19941363 　

ISSN： 0013-5194

eISSN： 1350-911X
SUBPICOSECOND OPTICAL DEMULTIPLEXING AT 10-GHZ WITH ZERO-DISPERSION, DISPERSION-FLATTENED, NONLINEAR FIBER LOOP MIRROR CONTROLLED BY 500FS GAIN-SWITCHED LASER-DIODE Peer-reviewed

E YAMADA, K SUZUKI, M NAKAZAWA

ELECTRONICS LETTERS　30　(23)　1966-1968　1994/11

ISSN： 0013-5194

eISSN： 1350-911X
FEMTOSECOND ERBIUM-DOPED FIBER LASER WITH NONLINEAR POLARIZATION ROTATION AND ITS SOLITON COMPRESSION Peer-reviewed

E YOSHIDA, Y KIMURA, M NAKAZAWA

JAPANESE JOURNAL OF APPLIED PHYSICS PART 1-REGULAR PAPERS BRIEF COMMUNICATIONS & REVIEW PAPERS　33　(10)　5779-5783　1994/10

DOI： 10.1143/JJAP.33.5779 　

ISSN： 0021-4922
GENERATION OF 1.2PS, 10GHZ PULSE-TRAIN FROM ALL-OPTICALLY MODELOCKED, ERBIUM FIBER RING LASER WITH ACTIVE NONLINEAR POLARIZATION ROTATION Peer-reviewed

EJ GREER, Y KIMURA, K SUZUKI, E YOSHIDA, M NAKAZAWA

ELECTRONICS LETTERS　30　(21)　1764-1765　1994/10

DOI： 10.1049/el:19941215 　

ISSN： 0013-5194

eISSN： 1350-911X
80GBIT/S SOLITON DATA-TRANSMISSION OVER 500KM WITH UNEQUAL AMPLITUDE SOLITONS FOR TIMING CLOCK EXTRACTION Peer-reviewed

M NAKAZAWA, E YOSHIDA, E YAMADA, K SUZUKI, T KITOH, M KAWACHI

ELECTRONICS LETTERS　30　(21)　1777-1778　1994/10

DOI： 10.1049/el:19941207 　

ISSN： 0013-5194

eISSN： 1350-911X
FEMTOSECOND SOLITON-INTERACTIONS IN A DISTRIBUTED ERBIUM-DOPED FIBER AMPLIFIER Peer-reviewed

K KUROKAWA, H KUBOTA, M NAKAZAWA

IEEE JOURNAL OF QUANTUM ELECTRONICS　30　(9)　2220-2226　1994/09

DOI： 10.1109/3.309886 　

ISSN： 0018-9197

eISSN： 1558-1713
ULTRASTABLE HARMONICALLY AND REGENERATIVELY MODE-LOCKED POLARIZATION-MAINTAINING ERBIUM FIBER RING LASER Peer-reviewed

M NAKAZAWA, E YOSHIDA, Y KIMURA

ELECTRONICS LETTERS　30　(19)　1603-1605　1994/09

DOI： 10.1049/el:19941072 　

ISSN： 0013-5194

eISSN： 1350-911X
Gain and Noise Characteristics of a 48 km-Long, Dispersion-Shifted, Distributed Erbium-Doped Fiber Amplifier with High Power Transmission Signals Peer-reviewed

Y. Kimura, M. Nakazawa

20th European Conference on Optical Communication, ECOC'94　963-967　1994/09
Single-polarization 80 Gbit/s soliton data transmission over 500 km with unequal amplitude solitons for timing clock extraction Peer-reviewed

M. Nakazawa, E. Yoshida, E. Yamada, K. Suzuki, T. Kitoh, M. Kawachi

20th European Conference on Optical Communication, ECOC'94　41-44　1994/09
REDUCTION OF AMPLIFIED SPONTANEOUS EMISSION FROM A TRANSMITTED SOLITON SIGNAL USING A NONLINEAR AMPLIFYING LOOP MIRROR AND A NONLINEAR-OPTICAL LOOP MIRROR Peer-reviewed

E YAMADA, M NAKAZAWA

IEEE JOURNAL OF QUANTUM ELECTRONICS　30　(8)　1842-1850　1994/08

DOI： 10.1109/3.301648 　

ISSN： 0018-9197

eISSN： 1558-1713
STRAIGHT-LINE SOLITON DATA-TRANSMISSION AT 20GBIT/S BEYOND GORDON-HAUS LIMIT Peer-reviewed

M NAKAZAWA, K SUZUKI, H KUBOTA, E YAMADA, Y KIMURA

ELECTRONICS LETTERS　30　(16)　1331-1333　1994/08

DOI： 10.1049/el:19940915 　

ISSN： 0013-5194

eISSN： 1350-911X
52 Femtosecond Pulse Generation using an Erbium-Doped Fiber Laser with a Pulse Compression Technique Peer-reviewed

E. Yoshida, Y. Kimura, M. Nakazawa

5th Optoelectronics Conference, OEC'94　13B1-2　1994/07
20 Gbit/s-3000 km Straight-Line Soliton Transmission Beyond Gordon-Haus Limit Peer-reviewed

M. Nakazawa, K. Suzuki, H. Kubota, E. Yamada, Y. Kimura

5th Optoelectronics Conference, OEC'94　PDI-3　1994/07
SOLITON TRANSMISSION IN TELECOMMUNICATION NETWORKS Peer-reviewed

M NAKAZAWA

IEEE COMMUNICATIONS MAGAZINE　32　(3)　34-41　1994/03

DOI： 10.1109/35.267439 　

ISSN： 0163-6804
Ultra-high Speed Optical Soliton Communication(招待講演) Invited Peer-reviewed

M. Nakazawa

International Workshop on Femtosecond Technology, FST'94　1994/02
Possibility of sub-Terabit soliton transmission using soliton control Invited Peer-reviewed

H. Kubota, M. Nakazawa

Optical Fiber Communication, OFC'94　WM1　1994/02
OPTICAL SOLITON COMMUNICATION-SYSTEM USING ERBIUM-DOPED FIBER AMPLIFIERS Peer-reviewed

K SUZUKI, E YAMADA, H KUBOTA, M NAKAZAWA

FIBER AND INTEGRATED OPTICS　13　(1)　45-64　1994

DOI： 10.1080/01468039408202221 　

ISSN： 0146-8030

eISSN： 1096-4681
Ultrahigh speed optical soliton communication(招待論文) Peer-reviewed

NAKAZAWA Masataka

O plus E　177　53-64　1994
Recent Progress in Optical Soliton Communication (Invited). Invited Peer-reviewed

中沢正隆

電子情報通信学会技術研究報告　94　(228(LQE94 33-42))　TuC1-1　1994

ISSN： 0913-5685
High-speed optical soliton communication using erbium-doped fiber amplifier and soliton transmission control(招待講演) Invited Peer-reviewed

M. Nakazawa

1993 International Symposium on Nonlinear Theory and its Applications, NOLTA'93　7.8　1993/12
ACTIVE Q-SWITCHING AND MODE-LOCKING IN A 1.53-MU-M FIBER RING LASER WITH SATURABLE ABSORPTION IN ERBIUM-DOPED FIBER AT 4.2-K Peer-reviewed

M NAKAZAWA, K SUZUKI, H KUBOTA, Y KIMURA

OPTICS LETTERS　18　(18)　1526-1528　1993/09

ISSN： 0146-9592

eISSN： 1539-4794
SOLITON TRANSMISSION WITH LONG AMPLIFIER SPACING UNDER SOLITON CONTROL Peer-reviewed

H KUBOTA, M NAKAZAWA

ELECTRONICS LETTERS　29　(20)　1780-1781　1993/09

DOI： 10.1049/el:19931185 　

ISSN： 0013-5194

eISSN： 1350-911X
Ultrahigh-speed optical soliton communication and soliton transmission control(招待講演) Invited Peer-reviewed

M. Nakazawa

Nonlinear Guided-wave phenomena　TuA1　1993/09
STRAIGHT-LINE SOLITON DATA TRANSMISSIONS OVER 2000 KM AT 20 GBIT/S AND 1000 KM AT 40 GBIT/S USING ERBIUM-DOPED FIBER AMPLIFIERS Peer-reviewed

M NAKAZAWA, K SUZUKI, E YAMADA, H KUBOTA, Y KIMURA

ELECTRONICS LETTERS　29　(16)　1474-1476　1993/08

DOI： 10.1049/el:19930985 　

ISSN： 0013-5194

eISSN： 1350-911X
FEMTOSECOND ERBIUM-DOPED FIBER LASERS AND A SOLITON COMPRESSION TECHNIQUE Peer-reviewed

E YOSHIDA, Y KIMURA, M NAKAZAWA

JAPANESE JOURNAL OF APPLIED PHYSICS PART 1-REGULAR PAPERS BRIEF COMMUNICATIONS & REVIEW PAPERS　32　(8)　3461-3466　1993/08

ISSN： 0021-4922
CONTINUUM SUPPRESSED, UNIFORMLY REPETITIVE 136 FS PULSE GENERATION FROM AN ERBIUM-DOPED FIBER LASER WITH NONLINEAR POLARIZATION ROTATION Peer-reviewed

M NAKAZAWA, E YOSHIDA, T SUGAWA, Y KIMURA

ELECTRONICS LETTERS　29　(15)　1327-1329　1993/07

DOI： 10.1049/el:19930890 　

ISSN： 0013-5194

eISSN： 1350-911X
SOLITON TRANSMISSION CONTROL IN TIME AND FREQUENCY DOMAINS Peer-reviewed

H KUBOTA, M NAKAZAWA

IEEE JOURNAL OF QUANTUM ELECTRONICS　29　(7)　2189-2197　1993/07

DOI： 10.1109/3.237493 　

ISSN： 0018-9197

eISSN： 1558-1713
Straight-line soliton data transmissions at 20 Gbit/s-2000 km and 40 Gbit/s-1000 km using erbium-doped fiber amplifiers Peer-reviewed

M. Nakazawa, K. Suzuki, E. Yamada, H. Kubota, Y. Kimura

Optical Amplifiers and Their Applications, OA&A'93　PD2　1993/07
20-30 GHz pulse train generation from a MQW electro-absorption intensity modulator Peer-reviewed

E. Yamada, K. Wakita, M. Nakazawa

Optical Amplifiers and Their Applications, OA&A'93　MD7　1993/07
Femtosecond soliton interaction with adiabatic soliton narrowing in a distributed erbium-doped fiber amplifier Peer-reviewed

K. Kurokawa, H. Kubota, M. Nakazawa

Optical Amplifiers and Their Applications, OA&A'93　TuB4　1993/07
30 GHZ PULSE-TRAIN GENERATION FROM A MULTIQUANTUM-WELL ELECTROABSORPTION INTENSITY MODULATOR Peer-reviewed

E YAMADA, K WAKITA, M NAKAZAWA

ELECTRONICS LETTERS　29　(10)　845-847　1993/05

DOI： 10.1049/el:19930565 　

ISSN： 0013-5194

eISSN： 1350-911X
1.6 PS PULSE GENERATION FROM A 1.3-MU-M PR3+-DOPED FLUORIDE FIBER LASER Peer-reviewed

T SUGAWA, E YOSHIDA, Y MIYAJIMA, M NAKAZAWA

ELECTRONICS LETTERS　29　(10)　902-903　1993/05

DOI： 10.1049/el:19930602 　

ISSN： 0013-5194

eISSN： 1350-911X
EXPERIMENTAL DEMONSTRATION OF SOLITON DATA-TRANSMISSION OVER UNLIMITED DISTANCES WITH SOLITON CONTROL IN TIME AND FREQUENCY DOMAINS Peer-reviewed

M NAKAZAWA, K SUZUKI, E YAMADA, H KUBOTA, Y KIMURA, M TAKAYA

ELECTRONICS LETTERS　29　(9)　729-730　1993/04

DOI： 10.1049/el:19930489 　

ISSN： 0013-5194

eISSN： 1350-911X
ULTRAHIGH SPEED OPTICAL SOLITON COMMUNICATION USING ERBIUM-DOPED FIBER AMPLIFIERS Peer-reviewed

E YAMADA, K SUZUKI, H KUBOTA, M NAKAZAWA

IEICE TRANSACTIONS ON COMMUNICATIONS　E76B　(4)　410-419　1993/04

ISSN： 0916-8516

eISSN： 1745-1345
SELF-Q-SWITCHING AND MODE-LOCKING IN A 1.53-MU-M FIBER RING LASER WITH SATURABLE ABSORPTION IN ERBIUM-DOPED FIBER AT 4.2-K Peer-reviewed

M NAKAZAWA, K SUZUKI, H KUBOTA, Y KIMURA

OPTICS LETTERS　18　(8)　613-615　1993/04

ISSN： 0146-9592

eISSN： 1539-4794
GAIN CHARACTERISTICS OF ERBIUM-DOPED FIBER AMPLIFIERS WITH HIGH ERBIUM CONCENTRATION Peer-reviewed

Y KIMURA, M NAKAZAWA

JAPANESE JOURNAL OF APPLIED PHYSICS PART 1-REGULAR PAPERS BRIEF COMMUNICATIONS & REVIEW PAPERS　32　(3A)　1120-1125　1993/03

ISSN： 0021-4922
Ultrahigh-speed optical soliton communication and new aspects of soliton transmission technology(招待講演) Invited Peer-reviewed

M. Nakazawa

Optical Fiber Communication, OFC'93　WC1　1993/02
Long-distance dynamic soliton transmission technology

Masataka Nakazawa, Eiichi Yamada, Hirokazu Kubota, Kazunori Suzuki

NTT R and D　42　(5)　661-668　1993

ISSN： 0915-2326
GENERATION OF 98FS OPTICAL PULSES DIRECTLY FROM AN ERBIUM-DOPED FIBER RING LASER AT 1.57-MU-M Peer-reviewed

M NAKAZAWA, E YOSHIDA, Y KIMURA

ELECTRONICS LETTERS　29　(1)　63-65　1993/01

DOI： 10.1049/el:19930042 　

ISSN： 0013-5194

eISSN： 1350-911X
Reduction of ASE noise from transmitted soliton signals with a nonlinear amplifying optical loop mirror Peer-reviewed

NAKAZAWA Masataka

IEICE of Japan　J76-C-I　(4)　81-88　1993
Publisher: The Institute of Electronics, Information and Communication Engineers
ISSN： 0915-1893
Soliton transmission control in time and frequency domains Peer-reviewed

NAKAZAWA Masataka

IEICE of Japan　J76-C-I　147-157　1993
PHYSICAL INTERPRETATION OF REDUCTION OF SOLITON INTERACTION FORCES BY BANDWIDTH LIMITED AMPLIFICATION - REPLY Peer-reviewed

M NAKAZAWA, H KUBOTA

ELECTRONICS LETTERS　29　(2)　226-227　1993/01

ISSN： 0013-5194

eISSN： 1350-911X
1.6 ps pulse generation from a 1.3µm Pr3+-doped fluoride fibre laser Peer-reviewed

T. Sugawa, E. Yoshida, Y. Miyajima, M. Nakazawa

Electronics Letters　29　(10)　902-903　1993

DOI： 10.1049/el:19930602 　

ISSN： 0013-5194
OPTICAL SOLITON TRANSMISSION TECHNOLOGY Invited Peer-reviewed

M NAKAZAWA

LEOS '93 CONFERENCE PROCEEDINGS　388-389　1993

ISSN： 1092-8081
SIGNIFICANT MODIFICATION OF FEMTOSECOND SOLITON INTERACTION IN GAIN MEDIUM BY SMALL SUBPULSES Peer-reviewed

K KUROKAWA, H KUBOTA, M NAKAZAWA

ELECTRONICS LETTERS　28　(25)　2334-2336　1992/12

ISSN： 0013-5194

eISSN： 1350-911X
SOLITON SELF-FREQUENCY SHIFT ACCELERATED BY FEMTOSECOND SOLITON INTERACTION Peer-reviewed

K KUROKAWA, H KUBOTA, M NAKAZAWA

ELECTRONICS LETTERS　28　(22)　2052-2054　1992/10

DOI： 10.1049/el:19921315 　

ISSN： 0013-5194

eISSN： 1350-911X
ELECTRON-BEAM VAPOR-DEPOSITED ERBIUM-DOPED GLASS WAVE-GUIDE LASER AT 1.53-MU-M Peer-reviewed

M NAKAZAWA, Y KIMURA

ELECTRONICS LETTERS　28　(22)　2054-2056　1992/10

DOI： 10.1049/el:19921316 　

ISSN： 0013-5194

eISSN： 1350-911X
FEMTOSECOND SOLITON TRANSMISSION CHARACTERISTICS IN AN ULTRALONG ERBIUM-DOPED FIBER AMPLIFIER WITH DIFFERENT PUMPING CONFIGURATIONS Peer-reviewed

K KUROKAWA, M NAKAZAWA

IEEE JOURNAL OF QUANTUM ELECTRONICS　28　(9)　1922-1929　1992/09

DOI： 10.1109/3.144485 　

ISSN： 0018-9197

eISSN： 1558-1713
GAIN CHARACTERISTICS OF ERBIUM-DOPED FIBER AMPLIFIERS WITH HIGH ERBIUM CONCENTRATION Peer-reviewed

Y KIMURA, M NAKAZAWA

ELECTRONICS LETTERS　28　(15)　1420-1422　1992/07

DOI： 10.1049/el:19920903 　

ISSN： 0013-5194

eISSN： 1350-911X
10 Gbit/s penalty-free soliton data transmission over 1200 km Peer-reviewed

E. Yamada, K. Suzuki, M. Nakazawa

Opto Electronics Conference, OEC'92　16A4-4　1992/07
Recent Progress on soliton transmission systems(招待講演) Invited Peer-reviewed

M. Nakazawa

Opto Electronics Conference, OEC'92　15A2-2　1992/07
INFINITE-DISTANCE SOLITON TRANSMISSION WITH SOLITON CONTROLS IN TIME AND FREQUENCY DOMAINS Peer-reviewed

M NAKAZAWA, H KUBOTA, E YAMADA, K SUZUKI

ELECTRONICS LETTERS　28　(12)　1099-1100　1992/06

DOI： 10.1049/el:19920694 　

ISSN： 0013-5194

eISSN： 1350-911X
PHYSICAL INTERPRETATION OF REDUCTION OF SOLITON INTERACTION FORCES BY BANDWIDTH LIMITED AMPLIFICATION Peer-reviewed

M NAKAZAWA, H KUBOTA

ELECTRONICS LETTERS　28　(10)　958-960　1992/05

DOI： 10.1049/el:19920608 　

ISSN： 0013-5194

eISSN： 1350-911X
20 GBIT/S, 1020KM PENALTY-FREE SOLITON DATA-TRANSMISSION USING ERBIUM-DOPED FIBER AMPLIFIERS Peer-reviewed

M NAKAZAWA, K SUZUKI, E YAMADA

ELECTRONICS LETTERS　28　(11)　1046-1047　1992/05

DOI： 10.1049/el:19920663 　

ISSN： 0013-5194

eISSN： 1350-911X
20 GBIT/S, 1020KM PENALTY-FREE SOLITON DATA-TRANSMISSION USING ERBIUM-DOPED FIBER AMPLIFIERS Peer-reviewed

M NAKAZAWA, K SUZUKI, E YAMADA

ELECTRONICS LETTERS　28　(11)　1046-1047　1992/05

ISSN： 0013-5194

eISSN： 1350-911X
Ultralong distance soliton transmission(招待講演) Invited Peer-reviewed

M. Nakazawa

Conference on Lasers and Electro Optics, CLEO'92　CWI1　1992/05
10 GBIT/S, 1200 KM ERROR-FREE SOLITON DATA-TRANSMISSION USING ERBIUM-DOPED FIBER AMPLIFIERS Peer-reviewed

M NAKAZAWA, K SUZUKI, E YAMADA, H KUBOTA, Y KIMURA

ELECTRONICS LETTERS　28　(9)　817-818　1992/04

DOI： 10.1049/el:19920517 　

ISSN： 0013-5194

eISSN： 1350-911X
Erbium-doped fibre amplifiers in femtosecond pulse generation and long-distance soliton communication(招待講演) Invited Peer-reviewed

M. Nakazawa

Mini-Symposium on Fibre Amplifiers for Communications, The Rank Prize Funds　1992/04
COHERENT PI-PULSE PROPAGATION WITH PULSE BREAKUP IN AN ERBIUM-DOPED FIBER WAVE-GUIDE AMPLIFIER Peer-reviewed

M NAKAZAWA, K SUZUKI, Y KIMURA, H KUBOTA

PHYSICAL REVIEW A　45　(5)　R2682-R2685　1992/03

DOI： 10.1103/PhysRevA.45.R2682 　

ISSN： 2469-9926

eISSN： 2469-9934
LASER DIODE-PUMPED FEMTOSECOND ERBIUM-DOPED FIBER LASER WITH A SUB-RING CAVITY FOR REPETITION RATE CONTROL Peer-reviewed

E YOSHIDA, Y KIMURA, M NAKAZAWA

APPLIED PHYSICS LETTERS　60　(8)　932-934　1992/02

DOI： 10.1063/1.106465 　

ISSN： 0003-6951

eISSN： 1077-3118
10 Gbit/s-1200 km single-pass soliton data transmission using erbium-doped fiber amplifiers Peer-reviewed

M. Nakazawa, K. Suzuki, E. Yamada, H. Kubota, Y. Kimura

Optical Fiber Communication, OFC'92　11　PD11　1992/02
Soliton transmission control in the time domain Peer-reviewed

H. Kubota, M. Nakazawa

Optical Fiber Communication, OFC'92　WC2　1992/02
Recent progress on optical soliton communication and future prospects(招待講演) Invited Peer-reviewed

M. Nakazawa

Optical Fiber Communication, OFC'92　WC1　1992/02
SELF-INDUCED-TRANSPARENCY SOLITONS IN AN ERBIUM-DOPED FIBER WAVE-GUIDE Peer-reviewed

M NAKAZAWA, Y KIMURA, K KUROKAWA, K SUZUKI

PHYSICAL REVIEW A　45　(1)　R23-R26　1992/01

DOI： 10.1103/PhysRevA.45.R23 　

ISSN： 1050-2947

eISSN： 1094-1622
PARTIAL SOLITON COMMUNICATION-SYSTEM Peer-reviewed

H KUBOTA, M NAKAZAWA

OPTICS COMMUNICATIONS　87　(1-2)　15-18　1992/01

DOI： 10.1016/0030-4018(92)90033-N 　

ISSN： 0030-4018

eISSN： 1873-0310
Self induced transparency soliton and coherent π pulse propagation in erbium-doped fibers and amplifiers Peer-reviewed

NAKAZAWA Masataka

Review of Laser Eng.　20　(8)　638-652　1992
Publisher: The Laser Society of Japan
DOI： 10.2184/lsj.20.8_638 　

ISSN： 0387-0200

More details Close

The recent development of erbium-doped fiber amplifiers has aroused great interest in the observation of coherent pulse propagation in resonant fiber waveguides. The self-induced transparency (SIT) soliton offers a possibility of pulse shaping and standardization that is different from nonlinear Schrodinger (NLS) soliton formation. The guiding of radiation by fiber structure eliminates diffraction effects and makes possible the interaction of the radiation over long distances. To date, however, there has been no report of experiments on SIT solitons and coherent π pulse propagation in a fiber waveguide. In this paper, we describe the observations of self-induced transparency solitons and coherent π pulse propagation in an erbium-doped resonant fiber waveguide. We also describe NLS soliton propagation and the coexistence of NLS and SIT solitons, which contribute to a complete understanding of nonlinear dispersive wave propagation in a resonant medium.
Soliton communication using erbium-doped fiber amplifiers Peer-reviewed

NAKAZAWA Masataka

Review of Laser Eng.　20　(8)　662-672　1992
Publisher: The Laser Society of Japan
DOI： 10.2184/lsj.20.8_662 　

ISSN： 0387-0200

More details Close

Recent progress in optical soliton communication using erbium-doped fiber amplifiers is described. Soliton data signals at 10 Gbit/s have been transmitted without error over 1200 km by using 24 EDFAs. New techniques for soliton control in the time and frequency domains are also described.
Femtosecond erbium fiber laser with a nonlinear amplifying loop mirror pumped by laser diodes and the repetition rate control of output pulses Peer-reviewed

NAKAZAWA Masataka

IECE of Japan　J75-C-I　(10)　613-621　1992
Publisher:
ISSN： 0915-1893
A NEW TECHNIQUE FOR OPTICAL SOLITON COMMUNICATION Peer-reviewed

H KUBOTA, E YAMADA, M NAKAZAWA

NTT REVIEW　3　(6)　64-67　1991/11

ISSN： 0915-2334
COEXISTENCE OF A SELF-INDUCED-TRANSPARENCY SOLITON AND A NONLINEAR SCHRODINGER SOLITON IN AN ERBIUM-DOPED FIBER Peer-reviewed

M NAKAZAWA, F YAMADA, H KUBOTA

PHYSICAL REVIEW A　44　(9)　5973-5987　1991/11

DOI： 10.1103/PhysRevA.44.5973 　

ISSN： 2469-9926

eISSN： 2469-9934
Self-induced transparency soliton propagation in an erbium-doped optical fiber waveguide Peer-reviewed

M. Nakazawa, Y. Kimura, K. Suzuki, K. Kurokawa, H. Kubota

Optical Society of America Annual Meeting, Postdeadline paper　PD11　1991/11

DOI： 10.1103/PhysRevA.45.R23 　
Erbium-doped fiber amplifiers for ultrashort pulse generation and optical soliton communication(招待講演) Invited Peer-reviewed

M. Nakazawa

Optical Society of America Annual Meeting, Invited paper　MT3　1991/11
LOW THRESHOLD, 290-FS ERBIUM-DOPED FIBER LASER WITH A NONLINEAR AMPLIFYING LOOP MIRROR PUMPED BY INGAASP LASER-DIODES Peer-reviewed

M NAKAZAWA, E YOSHIDA, Y KIMURA

APPLIED PHYSICS LETTERS　59　(17)　2073-2075　1991/10

DOI： 10.1063/1.106134 　

ISSN： 0003-6951

eISSN： 1077-3118
FEMTOSECOND OPTICAL SOLITON TRANSMISSION OVER LONG DISTANCES USING ADIABATIC TRAPPING AND SOLITON STANDARDIZATION Peer-reviewed

M NAKAZAWA, H KUBOTA, K KUROKAWA, E YAMADA

JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS　8　(9)　1811-1817　1991/09

DOI： 10.1364/JOSAB.8.001811 　

ISSN： 0740-3224

eISSN： 1520-8540
FEMTOSECOND SOLITON TRANSMISSION IN 18-KM ERBIUM-DOPED FIBER AMPLIFIER WITH DIFFERENT PUMPING CONFIGURATIONS Peer-reviewed

K KUROKAWA, M NAKAZAWA

ELECTRONICS LETTERS　27　(19)　1765-1766　1991/09

DOI： 10.1049/el:19911098 　

ISSN： 0013-5194

eISSN： 1350-911X
HIGH-GAIN CHARACTERISTICS OF AN ERBIUM-DOPED FIBER AMPLIFIER PUMPED IN THE 800-NM BAND Peer-reviewed

Y KIMURA, E YOSHIDA, M NAKAZAWA

JAPANESE JOURNAL OF APPLIED PHYSICS PART 1-REGULAR PAPERS BRIEF COMMUNICATIONS & REVIEW PAPERS　30　(9A)　1995-2001　1991/09

ISSN： 0021-4922
Repetition rate control of an LD-pumped femtosecond erbium-doped fiber laser using a sub ring cavity Peer-reviewed

M. Nakazawa, E. Yamada, Y. Kimura

Nonlinear Guided-Wave Phenomena, PDP-9　PDP-9　1991/09
OBSERVATION OF NONLINEAR-INTERACTIONS IN 20 GBIT/S SOLITON TRANSMISSION OVER 500 KM USING ERBIUM-DOPED FIBER AMPLIFIERS Peer-reviewed

M NAKAZAWA, K SUZUKI, E YAMADA, H KUBOTA

ELECTRONICS LETTERS　27　(18)　1662-1663　1991/08

DOI： 10.1049/el:19911038 　

ISSN： 0013-5194

eISSN： 1350-911X
10 GBIT/S SOLITON DATA-TRANSMISSION OVER ONE MILLION KILOMETERS Peer-reviewed

M NAKAZAWA, E YAMADA, H KUBOTA, K SUZUKI

ELECTRONICS LETTERS　27　(14)　1270-1272　1991/07

DOI： 10.1049/el:19910796 　

ISSN： 0013-5194

eISSN： 1350-911X
10 GBIT/S SINGLE-PASS SOLITON TRANSMISSION OVER 1000 KM Peer-reviewed

E YAMADA, K SUZUKI, M NAKAZAWA

ELECTRONICS LETTERS　27　(14)　1289-1291　1991/07

DOI： 10.1049/el:19910807 　

ISSN： 0013-5194

eISSN： 1350-911X
FEMTOSECOND SOLITON TRANSMISSION IN 18KM-LONG DISPERSION-SHIFTED, DISTRIBUTED ERBIUM-DOPED FIBER AMPLIFIER Peer-reviewed

M NAKAZAWA, K KUROKAWA

ELECTRONICS LETTERS　27　(15)　1369-1371　1991/07

DOI： 10.1049/el:19910861 　

ISSN： 0013-5194

eISSN： 1350-911X
Gain characteristics of Lanthanum co-doped erbium fiber amplifier Peer-reviewed

Y. Kimura, M. Nakazawa

Optical Amplifiers and Their Applications, OA&A'91　WD5　1991/07
RECENT PROGRESS ON OPTICAL SOLITON COMMUNICATION Peer-reviewed

H KUBOTA, M NAKAZAWA

IEICE TRANSACTIONS ON COMMUNICATIONS ELECTRONICS INFORMATION AND SYSTEMS　74　(6)　1373-1378　1991/06

ISSN： 0917-1673
WAVELENGTH-DEPENDENT AMPLIFICATION CHARACTERISTICS OF FEMTOSECOND ERBIUM-DOPED OPTICAL FIBER AMPLIFIERS Peer-reviewed

K KUROKAWA, M NAKAZAWA

APPLIED PHYSICS LETTERS　58　(25)　2871-2873　1991/06

DOI： 10.1063/1.104758 　

ISSN： 0003-6951

eISSN： 1077-3118
LANTHANUM CODOPED ERBIUM FIBER AMPLIFIER Peer-reviewed

M NAKAZAWA, Y KIMURA

ELECTRONICS LETTERS　27　(12)　1065-1067　1991/06

DOI： 10.1049/el:19910661 　

ISSN： 0013-5194

eISSN： 1350-911X
COEXISTENCE OF SELF-INDUCED TRANSPARENCY SOLITON AND NONLINEAR SCHRODINGER SOLITON Peer-reviewed

M NAKAZAWA, E YAMADA, H KUBOTA

PHYSICAL REVIEW LETTERS　66　(20)　2625-2628　1991/05

DOI： 10.1103/PhysRevLett.66.2625 　

ISSN： 0031-9007

eISSN： 1079-7114
Femtosecond optical pulse transmission over long distances using adiabatic soliton trapping and soliton standardization Peer-reviewed

H. Kubota, M. Nakazawa, K. Kurokawa

Optical Fiber Communication, OFC'91　TuK1　1991/02
Dynamic soliton communication(招待講演) Invited Peer-reviewed

M. Nakazawa

Optical Fiber Communication, OFC'91　TuL1　1991/02
Soliton amplification and transmission with Er3+-doped fibre repeater pumped by GaInAsP laser diode

Masataka Nakazawa, Yasuo Kimura, Kazunori Suzuki

NTT R and D　40　(6)　865-868　1991

ISSN： 0915-2326
NOISE-FIGURE CHARACTERISTICS OF ER3+-DOPED FIBER AMPLIFIER PUMPED IN 0.8 MU-M BAND Peer-reviewed

Y KIMURA, K SUZUKI, M NAKAZAWA

ELECTRONICS LETTERS　27　(2)　146-148　1991/01

DOI： 10.1049/el:19910095 　

ISSN： 0013-5194

eISSN： 1350-911X
AUTOMATIC INTENSITY CONTROL OF AN OPTICAL-TRANSMISSION LINE USING ENHANCED GAIN SATURATION IN CASCADED OPTICAL AMPLIFIERS Peer-reviewed

E YAMADA, M NAKAZAWA

IEEE JOURNAL OF QUANTUM ELECTRONICS　27　(1)　146-151　1991/01

DOI： 10.1109/3.73553 　

ISSN： 0018-9197

eISSN： 1558-1713
Stabilization of optical output power using gain saturation of EDFA and its application to soliton communication Peer-reviewed

NAKAZAWA Masataka

IECE of Japan(in Japanese)　J74-C-I　167-175　1991
Optical soliton transmission(招待論文) Peer-reviewed

NAKAZAWA Masataka

IECE of Japan　J74-C-I　429-439　1991
NOISE-FIGURE CHARACTERISTICS OF ER3+-DOPED FIBER AMPLIFIER PUMPED IN 0.8 MU-M BAND Peer-reviewed

Y KIMURA, K SUZUKI, M NAKAZAWA

ELECTRONICS LETTERS　27　(2)　146-148　1991/01

DOI： 10.1049/el:19910095 　

ISSN： 0013-5194

eISSN： 1350-911X
OPTICAL SOLITON COMMUNICATION USING ERBIUM-DOPED FIBER AMPLIFIERS Invited Peer-reviewed

M NAKAZAWA

IOOC-ECOC 91, PTS 1-4　A150-A164　1991
ULTRA-EFFICIENT ERBIUM-DOPED FIBER AMPLIFIER Peer-reviewed

Y KIMURA, M NAKAZAWA, K SUZUKI

APPLIED PHYSICS LETTERS　57　(25)　2635-2637　1990/12

DOI： 10.1063/1.103831 　

ISSN： 0003-6951

eISSN： 1077-3118
DYNAMIC OPTICAL SOLITON COMMUNICATION Peer-reviewed

M NAKAZAWA, K SUZUKI, H KUBOTA, E YAMADA, Y KIMURA

IEEE JOURNAL OF QUANTUM ELECTRONICS　26　(12)　2095-2102　1990/12

DOI： 10.1109/3.64344 　

ISSN： 0018-9197

eISSN： 1558-1713
ULTRALONG DISPERSION-SHIFTED ERBIUM-DOPED FIBER AMPLIFIER AND ITS APPLICATION TO SOLITON TRANSMISSION Peer-reviewed

M NAKAZAWA, Y KIMURA, K SUZUKI

IEEE JOURNAL OF QUANTUM ELECTRONICS　26　(12)　2103-2108　1990/12

DOI： 10.1109/3.64345 　

ISSN： 0018-9197

eISSN： 1558-1713
GAIN-DISTRIBUTION MEASUREMENTS ALONG AN ULTRALONG ERBIUM-DOPED FIBER AMPLIFIER USING OPTICAL-TIME-DOMAIN REFLECTOMETRY Peer-reviewed

M NAKAZAWA, Y KIMURA, K SUZUKI

OPTICS LETTERS　15　(21)　1200-1202　1990/11

DOI： 10.1364/OL.15.001200 　

ISSN： 0146-9592

eISSN： 1539-4794
HIGH-POWER ER-3+-DOPED FIBER AMPLIFIER PUMPED BY 1.48-MU-M LASER-DIODES Peer-reviewed

K SUZUKI, Y KIMURA, M NAKAZAWA

JAPANESE JOURNAL OF APPLIED PHYSICS PART 2-LETTERS & EXPRESS LETTERS　29　(11)　L2067-L2069　1990/11

ISSN： 0021-4922
EFFICIENT ERBIUM-DOPED FIBER AMPLIFIER PUMPED AT 820 NM Peer-reviewed

M NAKAZAWA, Y KIMURA, E YOSHIDA, K SUZUKI

ELECTRONICS LETTERS　26　(23)　1936-1938　1990/11

DOI： 10.1049/el:19901253 　

ISSN： 0013-5194

eISSN： 1350-911X
FEMTOSECOND OPTICAL PULSE GENERATION USING A DISTRIBUTED-FEEDBACK LASER DIODE Peer-reviewed

M NAKAZAWA, K SUZUKI, E YAMADA

ELECTRONICS LETTERS　26　(24)　2038-2040　1990/11

DOI： 10.1049/el:19901315 　

ISSN： 0013-5194

eISSN： 1350-911X
Optical soliton transmission and femtosecond pulse technology Peer-reviewed

M. Nakazawa

NTT International Symposium'90　119-133　1990/11
OBSERVATION OF THE TRAPPING OF AN OPTICAL SOLITON BY ADIABATIC GAIN NARROWING AND ITS ESCAPE Peer-reviewed

M NAKAZAWA, K KUROKAWA, H KUBOTA, E YAMADA

PHYSICAL REVIEW LETTERS　65　(15)　1881-1884　1990/10

DOI： 10.1103/PhysRevLett.65.1881 　

ISSN： 0031-9007

eISSN： 1079-7114
Optical soliton communication Peer-reviewed

M. Nakazawa

The Second International Forum on the Frontier of Telecommunications Technology　1-7　1990/10
20 GBIT/S SOLITON TRANSMISSION OVER 200 KM USING ERBIUM-DOPED FIBER REPEATERS Peer-reviewed

M NAKAZAWA, K SUZUKI, E YAMADA, Y KIMURA

ELECTRONICS LETTERS　26　(19)　1592-1593　1990/09

DOI： 10.1049/el:19901020 　

ISSN： 0013-5194

eISSN： 1350-911X
The dawn of optical soliton communication(招待講演) Invited Peer-reviewed

M. Nakazawa

Mini-Symposium on Nonlinear optical Fibre Pulse Processing, The Rank Prize Funds　WE-14　1990/09
FEMTOSECOND ERBIUM-DOPED OPTICAL FIBER AMPLIFIER Peer-reviewed

M NAKAZAWA, K KUROKAWA, H KUBOTA, K SUZUKI, Y KIMURA

APPLIED PHYSICS LETTERS　57　(7)　653-655　1990/08

DOI： 10.1063/1.104102 　

ISSN： 0003-6951

eISSN： 1077-3118
MAXIMUM TRANSMISSION CAPACITY OF A SOLITON COMMUNICATION-SYSTEM WITH LUMPED AMPLIFIERS Peer-reviewed

H KUBOTA, M NAKAZAWA

ELECTRONICS LETTERS　26　(18)　1454-1456　1990/08

DOI： 10.1049/el:19900933 　

ISSN： 0013-5194

eISSN： 1350-911X
An ultra-efficient erbium-doped fiber amplifier of 10.2 dB/mW at 0.98 μm pumping and 5.1 dB/mW at 1.48 μm pumping Peer-reviewed

M. Nakazawa, Y. Kimura, K. Suzuki

Optical Amplifiers and Their Applications, OA&A'90　PDP1　1990/08
High gain erbium-doped fiber amplifier pumped by 820 nm GaAlAs laser diode Peer-reviewed

K. Suzuki, Y. Kimura, M. Nakazawa

Optical Amplifiers and Their Applications, OA&A'90　MB4　1990/08
Soliton transmission in a distributed, dispersion-shifted erbium-doped fiber amplifier Peer-reviewed

M. Nakazawa, Y. Kimura, K. Suzuki

Optical Amplifiers and Their Applications, OA&A'90　7　TuA7　1990/08
AUTOMATIC OPTICAL SOLITON CONTROL USING CASCADED ER-3+-DOPED FIBER AMPLIFIERS Peer-reviewed

K SUZUKI, M NAKAZAWA

ELECTRONICS LETTERS　26　(14)　1032-1034　1990/07

DOI： 10.1049/el:19900669 　

ISSN： 0013-5194

eISSN： 1350-911X
TRANSFORM-LIMITED PULSE GENERATION IN THE GIGAHERTZ REGION FROM A GAIN-SWITCHED DISTRIBUTED-FEEDBACK LASER DIODE USING SPECTRAL WINDOWING Peer-reviewed

M NAKAZAWA, K SUZUKI, Y KIMURA

OPTICS LETTERS　15　(12)　715-717　1990/06

DOI： 10.1364/OL.15.000715 　

ISSN： 0146-9592

eISSN： 1539-4794
HIGH-GAIN ER-3+-DOPED FIBER AMPLIFIER PUMPED BY 820 NM GAALAS LASER-DIODES Peer-reviewed

K SUZUKI, Y KIMURA, M NAKAZAWA

ELECTRONICS LETTERS　26　(13)　948-949　1990/06

DOI： 10.1049/el:19900618 　

ISSN： 0013-5194

eISSN： 1350-911X
GENERATION AND TRANSMISSION OF OPTICAL SOLITONS IN THE GIGAHERTZ REGION USING A DIRECTLY MODULATED DISTRIBUTED-FEEDBACK LASER DIODE Peer-reviewed

M NAKAZAWA, K SUZUKI, Y KIMURA

OPTICS LETTERS　15　(10)　588-590　1990/05

DOI： 10.1364/OL.15.000588 　

ISSN： 0146-9592

eISSN： 1539-4794
Propagation and amplification of ultrashort optical soliton pulses in erbium-doped fibers for very high speed communication(招待講演) Invited Peer-reviewed

M. Nakazawa

Topical Meeting on Ultrafast Phenomena, ICUP'90　ThA2-1　1990/05
LONG-DISTANCE OPTICAL SOLITON TRANSMISSION WITH LUMPED AMPLIFIERS Peer-reviewed

H KUBOTA, M NAKAZAWA

IEEE JOURNAL OF QUANTUM ELECTRONICS　26　(4)　692-700　1990/04

DOI： 10.1109/3.53386 　

ISSN： 0018-9197

eISSN： 1558-1713
PUMP WAVELENGTH DEPENDENCE OF THE GAIN FACTOR IN 1.48 MU-M PUMPED ER-3+-DOPED FIBER AMPLIFIERS Peer-reviewed

Y KIMURA, K SUZUKI, M NAKAZAWA

APPLIED PHYSICS LETTERS　56　(17)　1611-1613　1990/04

DOI： 10.1063/1.103141 　

ISSN： 0003-6951

eISSN： 1077-3118
5 GBIT/S, 250KM ERROR-FREE SOLITON TRANSMISSION WITH ER3+-DOPED FIBER AMPLIFIERS AND REPEATERS Peer-reviewed

K SUZUKI, M NAKAZAWA, E YAMADA, Y KIMURA

ELECTRONICS LETTERS　26　(8)　551-553　1990/04

DOI： 10.1049/el:19900359 　

ISSN： 0013-5194

eISSN： 1350-911X
HIGH-GAIN ERBIUM FIBER AMPLIFIER PUMPED BY 800NM BAND Peer-reviewed

M NAKAZAWA, Y KIMURA, K SUZUKI

ELECTRONICS LETTERS　26　(8)　548-550　1990/04

DOI： 10.1049/el:19900357 　

ISSN： 0013-5194

eISSN： 1350-911X
3.2-5 GB/S, 100 KM ERROR-FREE SOLITON TRANSMISSIONS WITH ERBIUM AMPLIFIERS AND REPEATERS Peer-reviewed

M NAKAZAWA, K SUZUKI, Y KIMURA

IEEE PHOTONICS TECHNOLOGY LETTERS　2　(3)　216-219　1990/03

DOI： 10.1109/68.50894 　

ISSN： 1041-1135
NEAR-INFRARED ULTRASHORT PULSE GENERATION WITH LINBO3 BY DIFFERENCE-FREQUENCY-GENERATION Peer-reviewed

K KUROKAWA, M NAKAZAWA, TA CAUGHEY

OPTICS COMMUNICATIONS　75　(5-6)　413-418　1990/03

ISSN： 0030-4018
Erbium-doped optical fiber amplifiers and thier applications Peer-reviewed

NAKAZAWA Masataka

Journal of Applied Physics　59　1175-1192　1990

DOI： 10.11470/oubutsu1932.59.1175 　
PROPAGATION AND AMPLIFICATION OF ULTRASHORT OPTICAL SOLITON PULSES IN ERBIUM-DOPED FIBERS FOR VERY HIGH-SPEED COMMUNICATION Peer-reviewed

M NAKAZAWA

ULTRAFAST PHENOMENA VII　53　(Ultrafast Phenomena VII)　179-183　1990
Distortion-free single-pass soliton communication over 250 km using multiple Er3+-doped optical repeaters Peer-reviewed

M. Nakazawa, K. Suzuki, E. Yamada, Y. Kimura

OFC'90　PD5　1990/01
Amplification and transmission at 1.53-1.55 μm with Er3+-doped fibers(招待講演) Invited Peer-reviewed

M. Nakazawa, Y. Kimura

Optical Fiber Communication, OFC'90　FA5　1990/01
HIGH-GAIN ERBIUM-DOPED FIBER AMPLIFIER PUMPED IN THE 0.8 MU-M PUMP BAND Peer-reviewed

Y KIMURA, K SUZUKI, M NAKAZAWA

16TH EUROPEAN CONFERENCE ON OPTICAL COMMUNICATION, VOLS 1-3　103-106　1990
FEMTOSECOND PULSE GENERATION IN THE 1300 - 1600 NM REGION AND APPLICATION TO OPTICAL COMMUNICATION Peer-reviewed

K KUROKAWA, M NAKAZAWA

16TH EUROPEAN CONFERENCE ON OPTICAL COMMUNICATION, VOLS 1-3　705-712　1990
PUMPING WAVELENGTH DEPENDENCE ON GAIN FACTOR OF A 0.98-MU-M PUMPED ER-3+ FIBER AMPLIFIER Peer-reviewed

K SUZUKI, Y KIMURA, M NAKAZAWA

APPLIED PHYSICS LETTERS　55　(25)　2573-2575　1989/12

DOI： 10.1063/1.101982 　

ISSN： 0003-6951

eISSN： 1077-3118
46.5DB GAIN IN ER3+-DOPED FIBER AMPLIFIER PUMPED BY 1.48-MU-M GAINASP LASER-DIODES Peer-reviewed

Y KIMURA, K SUZUKI, M NAKAZAWA

ELECTRONICS LETTERS　25　(24)　1656-1657　1989/11

DOI： 10.1049/el:19891110 　

ISSN： 0013-5194

eISSN： 1350-911X
WAVELENGTH MULTIPLE SOLITON AMPLIFICATION AND TRANSMISSION WITH AN ER-3+-DOPED OPTICAL FIBER Peer-reviewed

M NAKAZAWA, Y KIMURA, K SUZUKI, H KUBOTA

JOURNAL OF APPLIED PHYSICS　66　(7)　2803-2812　1989/10

DOI： 10.1063/1.344208 　

ISSN： 0021-8979

eISSN： 1089-7550
20-GHZ SOLITON AMPLIFICATION AND TRANSMISSION WITH AN ER3+-DOPED FIBER Peer-reviewed

M NAKAZAWA, K SUZUKI, Y KIMURA

OPTICS LETTERS　14　(19)　1065-1067　1989/10

DOI： 10.1364/OL.14.001065 　

ISSN： 0146-9592

eISSN： 1539-4794
GENERATION OF 72-FS PULSE FROM A CAVITY DUMPED, SYNCHRONOUSLY PUMPED DYE-LASER WITH A SINGLE JET Peer-reviewed

K KUROKAWA, H KUBOTA, M NAKAZAWA

OPTICS COMMUNICATIONS　73　(4)　319-321　1989/10

DOI： 10.1016/0030-4018(89)90225-3 　

ISSN： 0030-4018

eISSN： 1873-0310
THE MODULATIONAL INSTABILITY LASER .1. EXPERIMENT Peer-reviewed

M NAKAZAWA, K SUZUKI, HA HAUS

IEEE JOURNAL OF QUANTUM ELECTRONICS　25　(9)　2036-2044　1989/09

DOI： 10.1109/3.35230 　

ISSN： 0018-9197

eISSN： 1558-1713
THE MODULATIONAL INSTABILITY LASER .2. THEORY Peer-reviewed

M NAKAZAWA, K SUZUKI, H KUBOTA, HA HAUS

IEEE JOURNAL OF QUANTUM ELECTRONICS　25　(9)　2045-2052　1989/09

DOI： 10.1109/3.35231 　

ISSN： 0018-9197

eISSN： 1558-1713
LASER-DIODE-PUMPED MIRROR-FREE ER-3+-DOPED FIBER LASER Peer-reviewed

Y KIMURA, K SUZUKI, M NAKAZAWA

OPTICS LETTERS　14　(18)　999-1001　1989/09

DOI： 10.1364/OL.14.000999 　

ISSN： 0146-9592

eISSN： 1539-4794
Erbium-doped fiber amplifier and its application to nonlinear optics(招待講演) Invited Peer-reviewed

M. Nakazawa

SPIE　1171　1989/09
SUBPICOSECOND SOLITON AMPLIFICATION AND TRANSMISSION USING ER-3+-DOPED FIBERS PUMPED BY INGAASP LASER-DIODES Peer-reviewed

K SUZUKI, Y KIMURA, M NAKAZAWA

OPTICS LETTERS　14　(16)　865-867　1989/08

ISSN： 0146-9592
FEMTOSECOND 1.4-1.6-MU-M INFRARED PULSE GENERATION AT A HIGH REPETITION RATE BY DIFFERENCE FREQUENCY GENERATION Peer-reviewed

K KUROKAWA, M NAKAZAWA

APPLIED PHYSICS LETTERS　55　(1)　7-9　1989/07

DOI： 10.1063/1.101759 　

ISSN： 0003-6951

eISSN： 1077-3118
20 Gb/s soliton amplification and transmission with an Er3+-doped fiber Peer-reviewed

M. Nakazawa, K. Suzuki, Y. Kimura

IOOC'89　20PDA-3　1989/07
Erbium-doped optical fiber amplifier(招待講演) Invited Peer-reviewed

M. Nakazawa

Workshop on Optical Amplification for Communications, in conjunction with IOOC'89　1989/07
Subpicosecond soliton amplification and transmission using Er3+-doped fiber pumped by InGaAsP laser diodes Peer-reviewed

K. Suzuki, Y. Kimura, M. Nakazawa

IOOC'89　20PDA-2　1989/07
Optical soliton amplification and transmission by stimulated Raman scattering pumped by InGaAsP laser diode Peer-reviewed

K. Suzuki, Y. Kimura, M. Nakazawa

IOOC'89　4　21C4-4　1989/07
Gain dynamics of an Er3+-doped fiber amplifier Peer-reviewed

Y. Kimura, K. Suzuki, M. Nakazawa

IOOC'89　3　20A4-6　1989/07
Femtosecond fiber Raman soliton and related technique(招待講演) Invited Peer-reviewed

M. Nakazawa

International conference on Integrated Optics and Optical Fiber Communication, IOOC'89　18A2-1　1989/07
HIGH-ORDER SOLITONS AND THE MODULATIONAL INSTABILITY Peer-reviewed

M NAKAZAWA, K SUZUKI, H KUBOTA, HA HAUS

PHYSICAL REVIEW A　39　(11)　5768-5776　1989/06

DOI： 10.1103/PhysRevA.39.5768 　

ISSN： 1050-2947
AN 8-MW CW ER-3+-DOPED FIBER LASER PUMPED BY 1.46 MU-M INGAASP LASER-DIODES Peer-reviewed

K SUZUKI, Y KIMURA, M NAKAZAWA

JAPANESE JOURNAL OF APPLIED PHYSICS PART 2-LETTERS & EXPRESS LETTERS　28　(6)　L1000-L1002　1989/06

ISSN： 0021-4922
250-KM NONREPEATED TRANSMISSION EXPERIMENT AT 1.8GB/S USING LD PUMPED ER3+-DOPED FIBER AMPLIFIERS IN IM DIRECT DETECTION SYSTEM Peer-reviewed

K HAGIMOTO, K IWATSUKI, A TAKADA, M NAKAZAWA, M SARUWATARI, K AIDA, K NAKAGAWA

ELECTRONICS LETTERS　25　(10)　662-664　1989/05

DOI： 10.1049/el:19890448 　

ISSN： 0013-5194

eISSN： 1350-911X
STUDY OF OPTICAL PULSE-COMPRESSION WITH HIGHER-ORDER NONLINEARITY AND DISPERSION Peer-reviewed

H KUBOTA, M NAKAZAWA

JAPANESE JOURNAL OF APPLIED PHYSICS PART 1-REGULAR PAPERS BRIEF COMMUNICATIONS & REVIEW PAPERS　28　(4)　609-614　1989/04

ISSN： 0021-4922
Parametric soliton laser Peer-reviewed

K. Suzuki, M. Nakazawa, H. A. Haus

Conference on Lasers and Electro Optics, CLEO'89　FA4　1989/04
PARAMETRIC SOLITON LASER Peer-reviewed

K SUZUKI, M NAKAZAWA, HA HAUS

OPTICS LETTERS　14　(6)　320-332　1989/03

ISSN： 0146-9592

eISSN： 1539-4794
THE PARAMETRIC SOLITON LASER WITH LOW PEDESTAL Peer-reviewed

K SUZUKI, M NAKAZAWA, HA HAUS

JAPANESE JOURNAL OF APPLIED PHYSICS PART 2-LETTERS & EXPRESS LETTERS　28　(2)　L256-L258　1989/02

DOI： 10.1143/JJAP.28.L256 　

ISSN： 0021-4922
The modulational instability laser(招待講演) Invited Peer-reviewed

M. Nakazawa

Nonlinear Guided-Wave Phenomenon : Physics and Applications　FA1-1　1989/02
A 212-km non-repeated transmission experiment at 1.8 Gb/s using LD pumped Er3+-doped fiber amplifiers in an IM/DD repeater systems Peer-reviewed

K. Hagimoto, M. Nakazawa

Optical Fiber Communication, OFC'89　15　PD15-4　1989/02

DOI： 10.1049/el:19890448 　
SOLITON AMPLIFICATION AND TRANSMISSION WITH ER-3+-DOPED FIBER REPEATER PUMPED BY GAINASP LASER DIODE Peer-reviewed

M NAKAZAWA, Y KIMURA, K SUZUKI

ELECTRONICS LETTERS　25　(3)　199-200　1989/02

ISSN： 0013-5194

eISSN： 1350-911X
Mode competition between 0.9-and 1.08 μm laser transition in a Nd3+-doped fiber laser Peer-reviewed

Y. Kimura, M. Nakazawa

Optical Fiber Communication, OFC'89　TUG8　1989/02
SOLITON AMPLIFICATION AND TRANSMISSION WITH ER-3+-DOPED FIBER REPEATER PUMPED BY GAINASP LASER DIODE Peer-reviewed

M NAKAZAWA, Y KIMURA, K SUZUKI

ELECTRONICS LETTERS　25　(3)　199-200　1989/02

DOI： 10.1049/el:19890143 　

ISSN： 0013-5194

eISSN： 1350-911X
Erbium-doped fiber amplifier and its application to nonlinear optics Peer-reviewed

NAKAZAWA Masataka

Proceedings of SPIE-The International Society for Optical Engineering　1171　328-345　1989
Efficient Er3+-doped optical fiber amplifier pumped by a 1.48 μm InGaAsP laser diode Peer-reviewed

Masataka Nakazawa, Yasuo Kimura, Kazunori Suzuki

Applied Physics Letters　54　(4)　295-297　1989

DOI： 10.1063/1.101448 　

ISSN： 0003-6951
Wavelength multiple soliton amplification and transmission with an Er 3+-doped optical fiber Peer-reviewed

Masataka Nakazawa, Yasuo Kimura, Kazunori Suzuki, Hirokazu Kubota

Journal of Applied Physics　66　(7)　2803-2812　1989

DOI： 10.1063/1.344208 　

ISSN： 0021-8979
EFFICIENT ER-3+-DOPED OPTICAL FIBER AMPLIFIER PUMPED BY A 1.48-MU-M INGAASP LASER DIODE Peer-reviewed

M NAKAZAWA, Y KIMURA, K SUZUKI

APPLIED PHYSICS LETTERS　54　(4)　295-297　1989/01

DOI： 10.1063/1.101448 　

ISSN： 0003-6951

eISSN： 1077-3118
MODULATIONAL INSTABILITY OSCILLATION IN NONLINEAR DISPERSIVE RING CAVITY Peer-reviewed

M NAKAZAWA, K SUZUKI, HA HAUS

PHYSICAL REVIEW A　38　(10)　5193-5196　1988/11

DOI： 10.1103/PhysRevA.38.5193 　

ISSN： 1050-2947
48 FS, 190 KW PULSE GENERATION FROM A CAVITY DUMPED, SYNCHRONOUSLY PUMPED DYE-LASER Peer-reviewed

K KUROKAWA, H KUBOTA, M NAKAZAWA

OPTICS COMMUNICATIONS　68　(4)　287-290　1988/10

DOI： 10.1016/0030-4018(88)90401-4 　

ISSN： 0030-4018
MULTIWAVELENGTH CW LASER OSCILLATION IN A ND-3+ AND ER-3+ DOUBLY DOPED FIBER LASER Peer-reviewed

Y KIMURA, M NAKAZAWA

APPLIED PHYSICS LETTERS　53　(14)　1251-1253　1988/10

DOI： 10.1063/1.100444 　

ISSN： 0003-6951

eISSN： 1077-3118
29-FSEC PULSE GENERATION FROM A LINEAR-CAVITY SYNCHRONOUSLY PUMPED DYE-LASER Peer-reviewed

H KUBOTA, K KUROKAWA, M NAKAZAWA

OPTICS LETTERS　13　(9)　749-751　1988/09

ISSN： 0146-9592

eISSN： 1539-4794
RAMAN AMPLIFICATION IN A P2O5-DOPED OPTICAL FIBER Peer-reviewed

K SUZUKI, M NAKAZAWA

OPTICS LETTERS　13　(8)　666-668　1988/08

ISSN： 0146-9592

eISSN： 1539-4794
LASING CHARACTERISTICS OF ER-3+-DOPED SILICA FIBERS FROM 1553 UP TO 1603 NM Peer-reviewed

Y KIMURA, M NAKAZAWA

JOURNAL OF APPLIED PHYSICS　64　(2)　516-520　1988/07

DOI： 10.1063/1.341990 　

ISSN： 0021-8979

eISSN： 1089-7550
Generation of 29-femtosecond pulses from a synchronously pumped dye laser and its cavity damping technique Peer-reviewed

M. Nakazawa, H. Kubota, K. Kurokawa

Sixth International Conference on Ultrafast Phenomena, ICUP'88　TUC3-1　1988/07
Multi-wavelength laser oscillations in a Nd3+ and Er3t doubly doped fiber laser Peer-reviewed

Y. Kimura, M. Nakazawa

IQEC'88　WK-7　1988/07
Raman amplification in P2O5 doped silica fibers Peer-reviewed

K. Suzuki, M. Nakazawa

IQEC'88　MP-43　1988/07
COMPENSATION OF NONLINEAR CHIRP GENERATED BY SELF-STEEPENING USING 3RD-ORDER DISPERSION OF A GRATING PAIR Peer-reviewed

H KUBOTA, M NAKAZAWA

OPTICS COMMUNICATIONS　66　(2-3)　79-82　1988/04

DOI： 10.1016/0030-4018(88)90037-5 　

ISSN： 0030-4018

eISSN： 1873-0310
EFFICIENT OPTICAL PULSE-COMPRESSION USING A PAIR OF BREWSTER-ANGLED TEO2 CRYSTAL PRISMS Peer-reviewed

M NAKAZAWA, T NAKASHIMA, H KUBOTA, S SEIKAI

JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS　5　(2)　215-221　1988/02

ISSN： 0740-3224

eISSN： 1520-8540
OPTICAL PULSE-COMPRESSION USING A TEO2 ACOUSTOOPTICAL LIGHT DEFLECTOR Peer-reviewed

M NAKAZAWA, T NAKASHIMA, H KUBOTA

OPTICS LETTERS　13　(2)　120-122　1988/02

ISSN： 0146-9592

eISSN： 1539-4794
Multimode-fiber-type optical directional coupler for OTDR by using acoustooptical deflector Peer-reviewed

NAKAZAWA Masataka

IECE of Japan　J71-B　547-554　1988
Frequency tuning characteristics of fiber Raman soliton laser Peer-reviewed

M. Nakazawa, K. Suzuki, H. Nakano, H. A. Haus

International Quantum Electronics Conference, IQEC'88　ThE-5　1988/01
The soliton laser(招待講演) Invited Peer-reviewed

M. Nakazawa

13th European workshop on Optical Waveguide Theory　1988/01
SIMULTANEOUS OSCILLATION AT 0.91-MU-M, 1.08-MU-M, AND 1.53-MU-M IN A FUSION-SPLICED FIBER LASER Peer-reviewed

M NAKAZAWA, Y KIMURA

APPLIED PHYSICS LETTERS　51　(22)　1768-1770　1987/11

DOI： 10.1063/1.98516 　

ISSN： 0003-6951

eISSN： 1077-3118
65-FEMTOSECOND PULSE GENERATION FROM A SYNCHRONOUSLY PUMPED DYE-LASER WITHOUT A COLLIDING-PULSE MODE-LOCKING TECHNIQUE Peer-reviewed

M NAKAZAWA, T NAKASHIMA, H KUBOTA, S SEIKAI

OPTICS LETTERS　12　(9)　681-683　1987/09

DOI： 10.1364/OL.12.000681 　

ISSN： 0146-9592

eISSN： 1539-4794
THEORY OF THE SYNCHRONOUSLY PUMPED FIBER RAMAN LASER WITH SELF-PHASE MODULATION Peer-reviewed

M NAKAZAWA, MS STIX, EP IPPEN, HA HAUS

JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS　4　(9)　1412-1421　1987/09

ISSN： 0740-3224

eISSN： 1520-8540
55-KW, 240-FS PULSE GENERATION FROM A CAVITY DUMPED, SYNCHRONOUSLY PUMPED DYE-LASER AND ITS APPLICATION TO PULSE-COMPRESSION Peer-reviewed

M NAKAZAWA, T NAKASHIMA, H KUBOTA, S SEIKAI

APPLIED PHYSICS LETTERS　51　(10)　728-730　1987/09

DOI： 10.1063/1.99006 　

ISSN： 0003-6951

eISSN： 1077-3118
NONLINEAR POLARIZATION CHANGES IN A BIREFRINGENT FIBER Peer-reviewed

Y KIMURA, M NAKAZAWA

JAPANESE JOURNAL OF APPLIED PHYSICS PART 1-REGULAR PAPERS BRIEF COMMUNICATIONS & REVIEW PAPERS　26　(9)　1503-1508　1987/09

ISSN： 0021-4922
LASING SPECTRUM OF P CO-DOPED ND-3+ SILICA FIBERS Peer-reviewed

Y KIMURA, M NAKAZAWA

JAPANESE JOURNAL OF APPLIED PHYSICS PART 2-LETTERS & EXPRESS LETTERS　26　(8)　L1253-L1254　1987/08

ISSN： 0021-4922
FIBEROPTIC NONLINEAR COHERENT COUPLER Peer-reviewed

Y KIMURA, M NAKAZAWA, S SEIKAI

IEEE JOURNAL OF QUANTUM ELECTRONICS　23　(8)　1261-1267　1987/08

DOI： 10.1109/JQE.1987.1073511 　

ISSN： 0018-9197

eISSN： 1558-1713
Optical time domain reflectometors in single-mode optical fibers(招待講演) Invited Peer-reviewed

M. Nakazawa

XXIInd General Assembly of the International Union of Radio-Science, URSI　1987/08
EFFECT OF STIMULATED RAMAN-SCATTERING ON PULSE-COMPRESSION CHARACTERISTICS Peer-reviewed

T NAKASHIMA, M NAKAZAWA, K NISHI, H KUBOTA

OPTICS LETTERS　12　(6)　404-406　1987/06

ISSN： 0146-9592

eISSN： 1539-4794
THEORY OF THE FIBER RAMAN SOLITON LASER Peer-reviewed

HA HAUS, M NAKAZAWA

JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS　4　(5)　652-660　1987/05

ISSN： 0740-3224
Optical pulse compression and soliton lasers.

NAKAZAWA Masataka

rle　15　(11)　869-886　1987
Publisher: The Laser Society of Japan
DOI： 10.2184/lsj.15.869 　

ISSN： 0387-0200

More details Close

Recent progress on optical pulse compression techniques, optical solitons, and soliton lasers has been discussed. It is shown that nonlinear pulse propagation in single-mode fibers, which includes self-phase modulation and group velocity dispersion, plays an important role in making linearly chirped rectangular pulses, resuiting in efficient compression with a grating pair. The self steepening effect, a third-order dispersion, and the stimulated Raman scattering, which would deteriorate the compression characteristics, have been discussed in dctail. For a negative GVD region, an optical soliton described with a nonlinear schrodinger equation can be creiatcd by balancing SPM with GVD. A soliton laser by means of a color center Iaser and a fiber Raman soliton laser are discussed in terms of a perturbation theory.
Nonlinear optics in optical fibers Peer-reviewed

NAKAZAWA Masataka

Journal of Applied Physics　56　(10)　1265-1288　1987
Publisher: The Japan Society of Applied Physics
DOI： 10.11470/oubutsu1932.56.1265 　

ISSN： 0369-8009
THEORY OF THE SYNCHRONOUSLY PUMPED FIBER RAMAN LASER Peer-reviewed

M NAKAZAWA, M KUZNETSOV, EP IPPEN

IEEE JOURNAL OF QUANTUM ELECTRONICS　22　(10)　1953-1966　1986/10

DOI： 10.1109/JQE.1986.1072892 　

ISSN： 0018-9197

eISSN： 1558-1713
OPTICAL FIBER CABLE MEASUREMENTS IN THE FIELD Peer-reviewed

N UESUGI, T HORIGUCHI, M NAKAZAWA, Y MURAKAMI

IEEE JOURNAL ON SELECTED AREAS IN COMMUNICATIONS　4　(5)　732-736　1986/08

DOI： 10.1109/JSAC.1986.1146373 　

ISSN： 0733-8716
THEORETICAL LIMIT OF REPEATER SPACING IN AN OPTICAL-TRANSMISSION LINE UTILIZING RAMAN AMPLIFICATION Peer-reviewed

T NAKASHIMA, S SEIKAI, M NAKAZAWA, Y NEGISHI

JOURNAL OF LIGHTWAVE TECHNOLOGY　4　(8)　1267-1272　1986/08

ISSN： 0733-8724
CONFIGURATION OF THE OPTICAL-TRANSMISSION LINE USING STIMULATED RAMAN-SCATTERING FOR SIGNAL LIGHT AMPLIFICATION Peer-reviewed

T NAKASHIMA, S SEIKAI, M NAKAZAWA

JOURNAL OF LIGHTWAVE TECHNOLOGY　4　(6)　569-573　1986/06

ISSN： 0733-8724

eISSN： 1558-2213
PHASE-SENSITIVE DETECTION ON LORENTZIAN LINE-SHAPE AND ITS APPLICATION TO FREQUENCY STABILIZATION OF LASERS Peer-reviewed

M NAKAZAWA

JOURNAL OF APPLIED PHYSICS　59　(7)　2297-2305　1986/04

DOI： 10.1063/1.336326 　

ISSN： 0021-8979
Theory of the Synchronously Pumped Fiber Raman Laser Peer-reviewed

Masataka Nakazawa, Mark Kuznetsov, Erich P. Ippen

IEEE Journal of Quantum Electronics　22　(10)　1953-1966　1986

DOI： 10.1109/JQE.1986.1072892 　

ISSN： 1558-1713 0018-9197
SELF-DETECTING OPTICAL-TIME-DOMAIN REFLECTOMETER FOR SINGLE-MODE FIBERS Peer-reviewed

M NAKAZAWA, T NAKASHIMA, S SEIKAI, M IKEDA

OPTICS LETTERS　10　(3)　157-159　1985

ISSN： 0146-9592

eISSN： 1539-4794
OPTICAL-TIME DOMAIN REFLECTOMETER WITH A LASER DIODE OPERATING AS LIGHT EMITTER PHOTODETECTOR Peer-reviewed

T NAKASHIMA, M NAKAZAWA, S SEIKAI

JAPANESE JOURNAL OF APPLIED PHYSICS PART 2-LETTERS & EXPRESS LETTERS　24　(2)　L135-L136　1985

DOI： 10.1143/JJAP.24.L135 　

ISSN： 0021-4922
SYNCHRONOUSLY PUMPED FIBER RAMAN GYROSCOPE Peer-reviewed

M NAKAZAWA

OPTICS LETTERS　10　(4)　193-195　1985

ISSN： 0146-9592
HIGHLY EFFICIENT RAMAN AMPLIFICATION IN A POLARIZATION-PRESERVING OPTICAL FIBER Peer-reviewed

M NAKAZAWA

APPLIED PHYSICS LETTERS　46　(7)　628-630　1985

DOI： 10.1063/1.95508 　

ISSN： 0003-6951
RAMAN AMPLIFICATION IN 1.4-1.5-MU-M SPECTRAL REGION IN POLARIZATION-PRESERVING OPTICAL FIBERS Peer-reviewed

M NAKAZAWA, T NAKASHIMA, S SEIKAI

JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS　2　(4)　515-521　1985

ISSN： 0740-3224

eISSN： 1520-8540
SUM-FREQUENCY GENERATION IN A POLARIZATION-PRESERVING OPTICAL FIBER Peer-reviewed

T NAKASHIMA, M NAKAZAWA, Y NEGISHI

JAPANESE JOURNAL OF APPLIED PHYSICS PART 2-LETTERS & EXPRESS LETTERS　24　(5)　L308-L310　1985

DOI： 10.1143/JJAP.24.L308 　

ISSN： 0021-4922
Polarization mode properties of an elliptical stress-cladding fiber Peer-reviewed

NAKAZAWA Masataka

Trans. IECE of Japan　E-68　277-283　1985
POLARIZATION-MODE-COUPLING MEASUREMENTS ALONG A SPLICED POLARIZATION-PRESERVING FIBER USING A BACKSCATTERING TECHNIQUE Peer-reviewed

M NAKAZAWA, N SHIBATA, T HORIGUCHI, S SEIKAI

JOURNAL OF THE OPTICAL SOCIETY OF AMERICA A-OPTICS IMAGE SCIENCE AND VISION　2　(7)　1066-1076　1985

ISSN： 1084-7529

eISSN： 1520-8532
A NOVEL TECHNIQUE FOR REDUCING POLARIZATION NOISE IN OPTICAL-TIME DOMAIN REFLECTOMETERS FOR SINGLE-MODE FIBERS Peer-reviewed

T HORIGUCHI, K SUZUKI, N SHIBATA, M NAKAZAWA, S SEIKAI

JOURNAL OF LIGHTWAVE TECHNOLOGY　3　(4)　901-908　1985

ISSN： 0733-8724

eISSN： 1558-2213
DEPENDENCE OF RAMAN GAIN ON RELATIVE INDEX DIFFERENCE FOR GEO2-DOPED SINGLE-MODE FIBERS Peer-reviewed

T NAKASHIMA, S SEIKAI, M NAKAZAWA

OPTICS LETTERS　10　(8)　420-422　1985

ISSN： 0146-9592

eISSN： 1539-4794
Measurement of polarization mode-coupling along a polarization-preserving optical fiber using a backscattering technique Peer-reviewed

NAKAZAWA Masataka

Jpn Soc. of Opt.　14　350-358　1985
130 km fault location at 1.55 μm by using Er glass laser Peer-reviewed

M. Nakazawa, M. Toku

CLEO'84　WH2　1984/06
Raman amplification for silica fiber(招待講演) Invited Peer-reviewed

M. Nakazawa

CLEO'84　FR2　1984/06
OPTICAL-TIME DOMAIN REFLECTOMETER AT A 1.3 APPROXIMATELY 1.7-MU-M WAVELENGTH REGION Peer-reviewed

M TOKUDA, M NAKAZAWA, T HORIGUCHI

JAPAN ANNUAL REVIEWS IN ELECTRONICS COMPUTERS & TELECOMMUNICATIONS　11　179-194　1984
ACTIVE TRANSMISSION-LINE - LIGHT AMPLIFICATION BY BACKWARD-STIMULATED RAMAN-SCATTERING IN POLARIZATION-MAINTAINING OPTICAL FIBER Peer-reviewed

M NAKAZAWA, M TOKUDA, Y NEGISHI, N UCHIDA

JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS　1　(1)　80-85　1984

ISSN： 0740-3224
CONTINUOUS-WAVE RAMAN OSCILLATION FOR A ND-3+-YAG INTRACAVITY FIBER LASER Peer-reviewed

M NAKAZAWA, M TOKUDA, N UCHIDA

JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS　1　(1)　86-90　1984

ISSN： 0740-3224
MEASUREMENTS OF POLARIZATION MODE COUPLINGS ALONG POLARIZATION-MAINTAINING SINGLE-MODE OPTICAL FIBERS Peer-reviewed

M NAKAZAWA, N SHIBATA, M TOKUDA, Y NEGISHI

JOURNAL OF THE OPTICAL SOCIETY OF AMERICA A-OPTICS IMAGE SCIENCE AND VISION　1　(3)　285-292　1984

ISSN： 0740-3232
AN ACOUSTOOPTICAL DIRECTIONAL COUPLER FOR AN OPTICAL TIME-DOMAIN REFLECTOMETER Peer-reviewed

T HORIGUCHI, M NAKAZAWA, M TOKUDA, N UCHIDA

JOURNAL OF LIGHTWAVE TECHNOLOGY　2　(2)　108-115　1984

ISSN： 0733-8724
1.55 MU-M OTDR FOR SINGLE-MODE OPTICAL FIBER LONGER THAN 110 KM Peer-reviewed

M NAKAZAWA, M TOKUDA, Y MORISHIGE, H TORATANI

ELECTRONICS LETTERS　20　(8)　323-325　1984

DOI： 10.1049/el:19840219 　

ISSN： 0013-5194
OUTPUT-STABILIZED HIGH-REPETITION-RATE 1.545-MU-M Q-SWITCHED ER-GLASS LASER Peer-reviewed

Y MORISHIGE, S KISHIDA, K WASHIO, H TORATANI, M NAKAZAWA

OPTICS LETTERS　9　(5)　147-149　1984

ISSN： 0146-9592
130-KM-LONG FAULT LOCATION FOR SINGLE-MODE OPTICAL FIBER USING 1.55-MU-M Q-SWITCHED ER.3+ - GLASS-LASER Peer-reviewed

M NAKAZAWA, M TOKUDA, K WASHIO, Y ASAHARA

OPTICS LETTERS　9　(7)　312-314　1984

DOI： 10.1364/OL.9.000312 　

ISSN： 0146-9592
AN OPTOELECTRONIC SELF-OSCILLATORY CIRCUIT WITH AN OPTICAL FIBER DELAYED FEEDBACK AND ITS INJECTION LOCKING TECHNIQUE Peer-reviewed

M NAKAZAWA, T NAKASHIMA, M TOKUDA

JOURNAL OF LIGHTWAVE TECHNOLOGY　2　(5)　719-730　1984

ISSN： 0733-8724
EFFICIENT MULTIPLE VISIBLE-LIGHT GENERATION IN A POLARIZATION-PRESERVING OPTICAL FIBER PUMPED BY A 1.064-MU-M YTTRIUM ALUMINUM GARNET LASER Peer-reviewed

M NAKAZAWA, T NAKASHIMA, S SEIKAI

APPLIED PHYSICS LETTERS　45　(8)　823-825　1984

DOI： 10.1063/1.95431 　

ISSN： 0003-6951
Lasing characteristics of a new type of laser with an ultralong optical fiber resonator

M. Nakazawa, M. Tokuda, N. Uchida

IOOC'83　29D3-16　1983/06
Acoustooptical switch for fault location Peer-reviewed

T. Horiguchi, M. Nakazawa, M. Tokuda

IOOC'83　30B3-3　1983/06
ANALYSES OF OPTICAL TIME-DOMAIN REFLECTOMETRY FOR SINGLE-MODE FIBERS AND OF POLARIZATION OPTICAL TIME-DOMAIN REFLECTOMETRY FOR POLARIZATION-MAINTAINING FIBERS Peer-reviewed

M NAKAZAWA, M TOKUDA, N UCHIDA

OPTICS LETTERS　8　(2)　130-132　1983

ISSN： 0146-9592
THEORY OF BACKWARD RAYLEIGH-SCATTERING IN POLARIZATION-MAINTAINING SINGLE-MODE FIBERS AND ITS APPLICATION TO POLARIZATION OPTICAL-TIME DOMAIN REFLECTOMETRY Peer-reviewed

M NAKAZAWA

IEEE JOURNAL OF QUANTUM ELECTRONICS　19　(5)　854-861　1983

DOI： 10.1109/JQE.1983.1071932 　

ISSN： 0018-9197
LASING CHARACTERISTICS OF A ND-3+-YAG LASER WITH A LONG OPTICAL-FIBER RESONATOR Peer-reviewed

M NAKAZAWA, M TOKUDA, N UCHIDA

JOURNAL OF THE OPTICAL SOCIETY OF AMERICA　73　(6)　838-842　1983

ISSN： 0030-3941
MEASUREMENT TECHNIQUE FOR SINGLE-MODE OPTICAL FIBER Peer-reviewed

M NAKAZAWA, K AOYAMA

REVIEW OF THE ELECTRICAL COMMUNICATIONS LABORATORIES　31　(3)　290-298　1983

ISSN： 0029-067X
MEASUREMENT OF THE FIBER LOSS SPECTRUM USING FIBER RAMAN OPTICAL-TIME-DOMAIN REFLECTOMETRY Peer-reviewed

M NAKAZAWA, M TOKUDA

APPLIED OPTICS　22　(12)　1910-1914　1983

ISSN： 0003-6935
RAYLEIGH BACKSCATTERING THEORY FOR SINGLE-MODE OPTICAL FIBERS Peer-reviewed

M NAKAZAWA

JOURNAL OF THE OPTICAL SOCIETY OF AMERICA　73　(9)　1175-1180　1983

ISSN： 0030-3941
CONTINUUM SPECTRUM GENERATION IN A MULTIMODE FIBER USING 2 PUMP BEAMS AT 1.3-MU-M WAVELENGTH REGION Peer-reviewed

M NAKAZAWA, M TOKUDA

JAPANESE JOURNAL OF APPLIED PHYSICS PART 2-LETTERS　22　(4)　L239-L241　1983
MEASUREMENT OF POLARIZATION MODE-COUPLING ALONG A POLARIZATION-MAINTAINING OPTICAL FIBER USING A BACKSCATTERING TECHNIQUE Peer-reviewed

M NAKAZAWA, M TOKUDA, Y NEGISHI

OPTICS LETTERS　8　(10)　546-548　1983

ISSN： 0146-9592
Long distance fault location system for single-mode and multi-mode fibers with 1.32 μm YAG laser(招待講演) Invited Peer-reviewed

M. Nakazawa, M. Tokuda, N. Uchida

CLEO'82　WL4　1982/04
OPTICAL-PHASE FLUCTUATIONS THERMALLY INDUCED IN A SINGLE-MODE OPTICAL FIBER Peer-reviewed

T MUSHA, J KAMIMURA, M NAKAZAWA

APPLIED OPTICS　21　(4)　694-698　1982

DOI： 10.1364/AO.21.000694 　

ISSN： 0003-6935
OPTICAL-TIME DOMAIN REFLECTOMETRY AT A WAVELENGTH OF 1.5 MU-M USING STIMULATED RAMAN-SCATTERING IN MULTIMODE, GRADED-INDEX OPTICAL FIBER Peer-reviewed

M NAKAZAWA, M TOKUDA, K WASHIO

JOURNAL OF APPLIED PHYSICS　53　(3)　1391-1393　1982

DOI： 10.1063/1.329869 　

ISSN： 0021-8979
FREQUENCY-CHARACTERISTICS OF SELF-SUSTAINED INTENSITY OSCILLATION OF A LASER DIODE USING A DELAYED ELECTRICAL FEEDBACK Peer-reviewed

M NAKAZAWA

IEEE JOURNAL OF QUANTUM ELECTRONICS　18　(7)　1050-1052　1982

DOI： 10.1109/JQE.1982.1071654 　

ISSN： 0018-9197
CONTINUOUS-WAVE LASER OSCILLATION WITH AN ULTRALONG OPTICAL-FIBER RESONATOR Peer-reviewed

M NAKAZAWA, M TOKUDA, N UCHIDA

JOURNAL OF THE OPTICAL SOCIETY OF AMERICA　72　(10)　1338-1344　1982

ISSN： 0030-3941
FM ELIMINATED CH4 LOCKED FREQUENCY STABILIZATION OF 3.39 MU-M HE-NE-LASER IN DUAL FEEDBACK-CONTROL Peer-reviewed

M NAKAZAWA, JI NAKAMURA, T MUSHA

IEEE JOURNAL OF QUANTUM ELECTRONICS　17　(1)　103-108　1981

DOI： 10.1109/JQE.1980.1070576 　

ISSN： 0018-9197
PHOTON PROBE FAULT LOCATOR FOR SINGLE-MODE OPTICAL FIBER USING AN ACOUSTOOPTICAL LIGHT DEFLECTOR Peer-reviewed

M NAKAZAWA, T TANIFUJI, M TOKUDA, N UCHIDA

IEEE JOURNAL OF QUANTUM ELECTRONICS　17　(7)　1264-1269　1981

DOI： 10.1109/JQE.1981.1071250 　

ISSN： 0018-9197
POLARIZATION BEAT LENGTH MEASUREMENT IN A SINGLE-MODE OPTICAL FIBER BY BACKWARD RAYLEIGH-SCATTERING Peer-reviewed

M NAKAZAWA, T HORIGUCHI, M TOKUDA, N UCHIDA

ELECTRONICS LETTERS　17　(15)　513-515　1981

DOI： 10.1049/el:19810359 　

ISSN： 0013-5194
SELF-SUSTAINED INTENSITY OSCILLATION OF A LASER DIODE INTRODUCED BY A DELAYED ELECTRICAL FEEDBACK USING AN OPTICAL FIBER AND AN ELECTRICAL AMPLIFIER Peer-reviewed

M NAKAZAWA, M TOKUDA, N UCHIDA

APPLIED PHYSICS LETTERS　39　(5)　379-381　1981

DOI： 10.1063/1.92744 　

ISSN： 0003-6951
PRELIMINARY EXPERIMENT FOR OPTICAL HETERODYNE COMMUNICATION WITH A SINGLE-MODE OPTICAL FIBER BY USING FREQUENCY-STABILIZED HE-NE LASERS Peer-reviewed

M NAKAZAWA, J KAMIMURA, T MUSHA

OPTICS LETTERS　6　(10)　508-510　1981

ISSN： 0146-9592
MARKED EXTENSION OF DIAGNOSIS LENGTH IN OPTICAL-TIME DOMAIN REFLECTOMETRY USING 1.32-MU-M YAG LASER Peer-reviewed

M NAKAZAWA, M TOKUDA, K WASHIO, Y MORISHIGE

ELECTRONICS LETTERS　17　(21)　783-785　1981

DOI： 10.1049/el:19810549 　

ISSN： 0013-5194
MEASUREMENT AND ANALYSIS ON POLARIZATION PROPERTIES OF BACKWARD RAYLEIGH-SCATTERING FOR SINGLE-MODE OPTICAL FIBERS Peer-reviewed

M NAKAZAWA, T HORIGUCHI, M TOKUDA, N UCHIDA

IEEE JOURNAL OF QUANTUM ELECTRONICS　17　(12)　2326-2334　1981

ISSN： 0018-9197
STABILITY MEASUREMENT OF THE 0.633 MU-M LINE IN A CH4-LOCKED 3.39 MU-M HE-NE-LASER Peer-reviewed

M NAKAZAWA, T MUSHA

JAPANESE JOURNAL OF APPLIED PHYSICS　19　(6)　L315-L317　1980

DOI： 10.1143/JJAP.19.L315 　

ISSN： 0021-4922
STABILITY OF FM-ELIMINATED 3.39 MU-M HE-NE-CH4 LASER Peer-reviewed

M NAKAZAWA, T MUSHA

JAPANESE JOURNAL OF APPLIED PHYSICS　19　(6)　L327-L329　1980

DOI： 10.1143/JJAP.19.L327 　

ISSN： 0021-4922

eISSN： 1347-4065
Frequency stabilization of a 3.39 μm He-Ne laser with no frequency modulation Peer-reviewed

NAKAZAWA Masataka

IECE of Japan　62-C　9-16　1979
Observation of saturated absorption of the 3.39 μm line in an external CH₄ cell Peer-reviewed

NAKAZAWA Masataka

Jpn. J. Appl. Phys.　18　597-602　1979
Frequency-stabilized 3.39 μm He-Ne laser with no frequency modulation Peer-reviewed

NAKAZAWA Masataka

J. Appl. Phys.　50　2544-2547　1979

DOI： 10.1063/1.326252 　
Frequency stabilization of 0.633 μm line with the aid of 3.39-μm line locked to CH₄ Peer-reviewed

NAKAZAWA Masataka

Appl. Phys. Lett.　35　745-747　1979

DOI： 10.1063/1.90954

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ISSN： 2432-6380
Quantum Noise Stream Cipher by Combining Mathematical and Physical Cryptographies

吉田真人, 中沢正隆

日本セキュリティ・マネジメント学会誌(Web)　39　(1)　2025

ISSN： 2434-5504
108 Gbit/s-64 QAM transmission over 10 km-SMF and 70 m wirelessly with a fully coherent method at IF-125 GHz

城市知輝, 葛西恵介, 吉田真人, 廣岡俊彦, 中沢正隆

電子情報通信学会技術研究報告(Web)　125　(59(OCS2025 11-22))　2025

ISSN： 2432-6380
All-Digital 16 QAM Nyquist Pulse Transmission over 4,000 km

芹川武貴, 芹川武貴, 吉田真人, 廣岡俊彦, 葛西恵介, 中沢正隆

電子情報通信学会大会講演論文集(CD-ROM)　2025　2025

ISSN： 1349-144X
108 Gbit/s-64 QAM fully coherent transmission over a 10 km-SMF and 10 m wirelessly at 125 GHz-IF

城市知輝, 葛西恵介, 吉田真人, 廣岡俊彦, 中沢正隆

電子情報通信学会大会講演論文集(CD-ROM)　2025　2025

ISSN： 1349-144X
An Oscillator-less Photonic Ising Machine with Digital-nonlinearity-based Bifurcation and Its Simulated Application to a 1 Million-node Fully Connected Max-cut Problem

中沢正隆, 廣岡俊彦

電子情報通信学会大会講演論文集(CD-ROM)　2025　2025

ISSN： 1349-144X
Application of optical communication and measurement technologies for multipoint field observations using compact absolute gravimeters

新谷錫人, 葛西恵介, 吉田真人, 中沢正隆

日本測地学会講演会要旨　144th　2025
126 Gbit/s-128 QAM fully coherent transmission over a 10 km-SMF and 10 m wirelessly using a direct sampling method

佐久間勇誠, 佐久間勇誠, 渡部新, 渡部新, 城市知輝, 城市知輝, 葛西恵介, 吉田真人, 吉田真人, 廣岡俊彦, 中沢正隆

電子情報通信学会大会講演論文集(CD-ROM)　2025　2025

ISSN： 1349-144X
Kerr-resonanced bifurcation switching in a photonic Ising machine with a long lossless optical fiber loop

中沢正隆, 廣岡俊彦

電子情報通信学会大会講演論文集(CD-ROM)　2025　2025

ISSN： 1349-144X
Recent Progress on Fiber and Transmission Technologies toward 3M Optical Communications

廣岡俊彦, 中沢正隆

レーザー研究　52　(9)　2024

ISSN： 0387-0200
Preface to Special Issue on Recent Progress of Optical Fiber Technologies for Realizing High-Speed, High-Capacity Communication

中沢正隆

レーザー研究　52　(9)　2024

ISSN： 0387-0200
Fully coherent optical and wireless transmission in the 28 GHz band by using an injection-locked carrier frequency converter

白幡晃一, 白幡晃一, 葛西恵介, 吉田真人, 廣岡俊彦, 中沢正隆, 東右一郎, 小林敏幸

電子情報通信学会技術研究報告(Web)　123　(330(OCS2023 57-66))　2024

ISSN： 2432-6380
EXAT研究会の15年の歩み

中沢正隆, 淡路祥成, 盛岡敏夫

ITUジャーナル(Web)　54　(6)　2024

ISSN： 2434-9712
1-Tb/s/λ PS-32QAM, 1,600 km Coherent Nyquist Optical Pulse Transmission with a Total Capacity of 21.5 Tb/s

石川碧人, 石川碧人, 別府翔平, 別府翔平, 別府翔平, 芹川武貴, 芹川武貴, 吉田真人, 廣岡俊彦, 中沢正隆

電子情報通信学会大会講演論文集(CD-ROM)　2024　2024

ISSN： 1349-144X
Performance comparison between injection-locking heterodyne detection and self-heterodyne detection in fully coherent optical and wireless transmission for optical mobile fronthaul at 28 GHz band

白幡晃一, 白幡晃一, 葛西恵介, 吉田真人, 廣岡俊彦, 中沢正隆, 東右一郎, 小林敏幸

電子情報通信学会大会講演論文集(CD-ROM)　2024　2024

ISSN： 1349-144X
Mode division multiplexed coherent optical transmission in time domain by using higher-order Hermite-Gaussian pulses

中沢正隆, 吉田真人, 廣岡俊彦

電子情報通信学会大会講演論文集(CD-ROM)　2024　2024

ISSN： 1349-144X
GAWBS noise characteristics in few-mode fiber supporting 6-LP modes

吉田哲也, 吉田哲也, 別府翔平, 別府翔平, 別府翔平, 吉田真人, 葛西恵介, 廣岡俊彦, 中沢正隆

電子情報通信学会大会講演論文集(CD-ROM)　2024　2024

ISSN： 1349-144X
108 Gbit/s-64 QAM fully coherent transmission over a 10 km-SMF and 10 m wirelessly in 30 GHz-IF

渡部新, 渡部新, 城市知輝, 葛西恵介, 吉田真人, 廣岡俊彦, 中沢正隆

電子情報通信学会大会講演論文集(CD-ROM)　2024　2024

ISSN： 1349-144X
Recent Progress on Fiber and Transmission Technologies toward 3M Optical Communications

HIROOKA Toshihiko, NAKAZAWA Masataka

The Review of Laser Engineering　52　(9)　446　2024
Publisher: The Laser Society of Japan
DOI： 10.2184/lsj.52.9_446 　

ISSN： 0387-0200

eISSN： 1349-6603

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This paper presents the latest developments in the 3M technologies for next-generation optical communication, namely Multi-level modulation, Multi-core fiber and Multi-mode control for mode-division multiplexing. We also describe recent innovative technologies including ultra-wideband WDM transmission beyond conventional C and L bands, and novel hollow-core fibers enabling ultra-low loss below conventional fibers.
Preface to Special Issue on Recent Progress of Optical Fiber Technologies for Realizing High-Speed, High-Capacity Communication

NAKAZAWA Masataka

The Review of Laser Engineering　52　(9)　444　2024
Publisher: The Laser Society of Japan
DOI： 10.2184/lsj.52.9_444 　

ISSN： 0387-0200

eISSN： 1349-6603

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This paper describes an overview of the special issue for recent research progress on optical fiber technologies for realizing high-speed, high-capacity communication with the use of so-called 3M technology. 3M technology means multi-level modulation, multi-core fiber and multi-mode control. The topics of the present issue cover recent trend of optical fiber technology, high-density multi-core fibers, submarine multi-core fibers, multi-core optical amplifiers, standardization of multi-core fibers, recent progress in high-density conventional optical fiber cables, and optical amplification fiber for satellite optical communication.
Coherently-linked optical and wireless transmission by using a 28 GHz band microstrip antenna

葛西恵介, 佐藤大晟, 佐藤大晟, 白幡晃一, 白幡晃一, 吉田真人, 廣岡俊彦, 中沢正隆, 東右一郎, 小林敏幸

電子情報通信学会技術研究報告(Web)　122　(378(AP2022 197-233))　2023

ISSN： 2432-6380
A proposal of radio IQ direct digital coherent transmission in mobile fronthaul

葛西恵介, 吉田真人, 廣岡俊彦, 中沢正隆, 松尾英範, 高橋領

電子情報通信学会大会講演論文集(CD-ROM)　2023　2023

ISSN： 1349-144X
Coherently-linked optical and wireless transmission using a 28 GHz band phased array microstrip antenna

佐藤大晟, 佐藤大晟, 葛西恵介, 白幡晃一, 白幡晃一, 吉田真人, 廣岡俊彦, 中沢正隆, 東右一郎, 小林敏幸

電子情報通信学会大会講演論文集(CD-ROM)　2023　2023

ISSN： 1349-144X
Evaluation of Radio and Optical Batch FEC in Radio IQ Direct Coherent Transmission

松尾英範, 高橋領, 牟田竜二, 松川潤也, 小杉正憲, 外山隆行, 葛西恵介, 中沢正隆

電子情報通信学会大会講演論文集(CD-ROM)　2023　2023

ISSN： 1349-144X
Application of Digital Coherent Optical Transmission Technology for Beyond 5G Mobile Fronthaul

葛西恵介, 吉田真人, 廣岡俊彦, 中沢正隆

電子情報通信学会誌　106　(6)　2023

ISSN： 0913-5693
Beyond5G/6Gでの活用が期待されるマルチコアファイバ〈2〉マルチコアファイバを収容した光海底ケーブルの評価技術の開発

吉田真人, 中沢正隆

光アライアンス　34　(12)　2023

ISSN： 0917-026X
Coherently-linked optical and wireless transmission over a 10 km SMF and 10 m wirelessly using 28 GHz microstrip array antennas

白幡晃一, 白幡晃一, 葛西恵介, 吉田真人, 廣岡俊彦, 中沢正隆, 東右一郎, 小林敏幸

電子情報通信学会大会講演論文集(CD-ROM)　2023　2023

ISSN： 1349-144X
Optical Network Weaved by Glass - Social Challenges and Future Prospects

Nakazawa Masataka

JSAP Annual Meetings Extended Abstracts　2022.2　49-49　2022/08/26
Publisher: The Japan Society of Applied Physics
DOI： 10.11470/jsapmeeting.2022.2.0_49 　

eISSN： 2436-7613
Optical Network Weaved by Glass-Social Challenges and Future Prospects-

中沢正隆

応用物理学会秋季学術講演会講演予稿集(CD-ROM)　83rd　2022

ISSN： 2758-4704
GAWBS Phase-Noise Correlation Characteristics Between Cores in 19-Core Fiber

佐藤耕造, 吉田真人, 葛西恵介, 廣岡俊彦, 中沢正隆

電子情報通信学会大会講演論文集(CD-ROM)　2022　2022

ISSN： 1349-144X
Evaluation technique of mode-coupling along a multi-core fiber with a multi-channel OTDR

吉田真人, 中沢正隆

電子情報通信学会大会講演論文集(CD-ROM)　2022　2022

ISSN： 1349-144X
Performance comparison between injection-locking type carrier frequency conversion and self-heterodyne detection methods in coherently-linked optical and wireless transmission

佐藤大晟, 佐藤大晟, 白幡晃一, 白幡晃一, 葛西恵介, 廣岡俊彦, 吉田真人, 中沢正隆

電子情報通信学会大会講演論文集(CD-ROM)　2022　2022

ISSN： 1349-144X
Optical and Wireless Linked Fully Coherent Access System toward Next Generation RAN

中沢正隆, 葛西恵介, 吉田真人, 廣岡俊彦

電子情報通信学会論文誌 C(Web)　J105-C　(11)　2022

ISSN： 1881-0217
光通信インフラの飛躍的な高度化に向けた3M技術の発展—Giant Leaps in Optical Communication Infrastructure Using 3 Multi Technologies

中沢正隆

Probo : advantest technical report = プロボー : アドバンテスト・テクニカル・レポート　(57)　4-9　2022
Publisher: 東京 : アドバンテストProbo編集室
Performance comparison of injection-locked carrier frequency conversion and self-heterodyne detection methods in cohelently-linked optical and wireless transmission

佐藤大晟, 佐藤大晟, 白幡晃一, 白幡晃一, 葛西恵介, 廣岡俊彦, 吉田真人, 中沢正隆

電子情報通信学会技術研究報告(Web)　121　(320(OCS2021 33-40))　2022

ISSN： 2432-6380
Recent progress and challenges toward ultrahigh-speed transmission beyond 10 Tbit/s with optical Nyquist pulses

Masataka Nakazawa, Masato Yoshida, Toshihiko Hirooka

IEICE ELECTRONICS EXPRESS　18　(7)　2021/04

DOI： 10.1587/elex.18.20212001 　

ISSN： 1349-2543
64 Gbit/s, 256 QAM coherently-linked optical and wireless transmission at 61 GHz-band using an injection-locked carrier frequency converter

佐藤大晟, 佐藤大晟, 葛西恵介, 廣岡俊彦, 吉田真人, 中沢正隆

電子情報通信学会大会講演論文集(CD-ROM)　2021　2021

ISSN： 1349-144X
GAWBS Noise Correlation Characteristics Between Cores in Four-Core Fiber

佐藤耕造, 吉田真人, 葛西恵介, 廣岡俊彦, 中沢正隆

電子情報通信学会大会講演論文集(CD-ROM)　2021　2021

ISSN： 1349-144X
Study on Chromatic Dispersion Dependence of GAWBS noise

佐藤耕造, 吉田真人, 葛西恵介, 廣岡俊彦, 中沢正隆

光通信システムシンポジウムプログラム&講演予稿集(CD-ROM)　35th　2021
Single-channel 1.28 Tbit/s Optical Nyquist Pulse Transmission over 3000 km

渡邊碧, 吉田真人, 廣岡俊彦, 中沢正隆

電子情報通信学会大会講演論文集(CD-ROM)　2021　2021

ISSN： 1349-144X
Performance comparison between Fabry-Perot LD based- and ECLD based-injection-locking circuits

葛西恵介, 管貴志, 吉田真人, 廣岡俊彦, 中沢正隆

電子情報通信学会大会講演論文集(CD-ROM)　2021　2021

ISSN： 1349-144X
10 GHz, 6.2 ps transform-limited coherent optical pulse generation from a 1.5 μm, self-injection gain-switched DFB-LD

葛西恵介, 中沢正隆

電子情報通信学会大会講演論文集(CD-ROM)　2020　2020

ISSN： 1349-144X
Experimental and theoretical analyses of GAWBS phase noise in multi-core fibers for digital coherent transmission

吉田真人, 竹節直也, 葛西恵介, 廣岡俊彦, 中沢正隆

電子情報通信学会技術研究報告(Web)　120　(140(OCS2020 4-7))　2020

ISSN： 2432-6380
光時分割多重(OTDM)研究が創出した最先端光技術とその将来展望—Advanced Photonic Technology for the Research of Optical Time-Division Multiplexing and Its Future Prospects

中沢正隆

電子情報通信学会誌 = The journal of the Institute of Electronics, Information and Communication Engineers　102　(8)　809-814　2019/08
Publisher: 東京 : 電子情報通信学会
ISSN： 0913-5693
GAWBS noise characteristics in digital coherent transmission in various optical fibers

竹節直也, 吉田真人, 葛西恵介, 廣岡俊彦, 中沢正隆

電子情報通信学会技術研究報告　119　(93(OCS2019 10-19)](Web))　2019

ISSN： 0913-5685
GAWBS noise influence for digital coherent transmission and its fiber dependence

竹節直也, 吉田真人, 葛西恵介, 廣岡俊彦, 中沢正隆

光通信システムシンポジウムプログラム&講演予稿集(CD-ROM)　33rd　2019
10ペタビット級光伝送実験の成功 (特集空間分割多重光通信技術の進展)

相馬大樹, 若山雄太, 別府翔平, 角田聖也, 釣谷剛宏, 林哲也, 永島拓志, 鈴木雅人, 吉田真人, 葛西恵介, 中沢正隆, 高橋英憲, 五十嵐浩司, 森田逸郎, 鈴木正敏

O plus E : Optics + electronics　40　(6)　724-728　2018/09
Publisher: アドコム・メディア
ISSN： 0911-5943
80 Gbit/s, 256 QAM Digital Coherent Optical Transmission with Injection-Locking for Next Generation Mobile Fronthaul

117　(423)　19-24　2018/01/29
Publisher: 電子情報通信学会
ISSN： 0913-5685
80 Gbit/s, 256 QAM Digital Coherent Optical Transmission with Injection-Locking for Next Generation Mobile Fronthaul

葛西恵介, WANG Yixin, 吉田真人, 廣岡俊彦, 岩月勝美, 中沢正隆

電子情報通信学会技術研究報告　117　(423(OCS2017 67-78))　2018

ISSN： 0913-5685
Single-channel 10.2 Tbit/s Optical Nyquist Pulse Transmission Over 300 km

平田綾也, WANG Jianping, 廣岡俊彦, 吉田真人, 中沢正隆

電子情報通信学会技術研究報告　118　(238(OFT2018 13-51)(Web))　2018

ISSN： 0913-5685
導波音響波型ブリルアン散乱(GAWBS)の観測とコヒーレントQAM伝送におけるそのデジタル補償

中沢正隆, 吉田真人, 寺山雅樹, 岡本聖司, 葛西恵介, 廣岡俊彦

電子情報通信学会大会講演論文集(CD-ROM)　2018　2018

ISSN： 1349-144X
光直交振幅変調による量子暗号通信

平野琢也, 並木亮, 中沢正隆, 吉田真人, 廣岡俊彦, 葛西恵介

応用物理学会春季学術講演会講演予稿集(CD-ROM)　64th　2017

ISSN： 2758-4704
High Spectral Efficient Transmission with Digital Coherent Ultra-multilevel QAM Format

45　(12)　466-471　2016/12
Publisher: 日本光学会
ISSN： 0389-6625
光ファイバネットワークを利用した地殻変動および津波計測 (特集防災とオプトメカトロニクス)

中沢正隆, 吉田真人, 葛西恵介

光技術コンタクト = Optical and electro-optical engineering contact　54　(12)　22-31　2016/12
Publisher: 光学工業技術協会
ISSN： 0913-7289
C-4-12 295 mW output, HCN frequency-stabilized CW erbium fiber ring laser

Kasai Keisuke, Yoshida Masato, Nakazawa Masataka

Proceedings of the IEICE General Conference　2016　(1)　216-216　2016/03/01
Publisher: The Institute of Electronics, Information and Communication Engineers
B-10-61 Q-factor analysis of dispersion and nonlinear impairments in ultrahigh-speed Nyquist pulse transmission

Hirooka Toshihiko, Nakazawa Masataka

Proceedings of the IEICE General Conference　2016　(2)　354-354　2016/03/01
Publisher: The Institute of Electronics, Information and Communication Engineers
B-10-52 320 Gbit/s, 256 QAM Coherent Optical Transmission over 160 km with an LD-based Injection-locked Homodyne Receiver

Wang Yixin, Kasai Keisuke, Yoshida Masato, Nakazawa Masataka

Proceedings of the IEICE General Conference　2016　(2)　345-345　2016/03/01
Publisher: The Institute of Electronics, Information and Communication Engineers
B-10-38 Real-time adaptive 4-64 QAM, 20-60 Gbit/s quantum noise stream cipher transmission

Nakazawa Masataka, Yoshida Masato, Hirooka Toshihiko, Kasai Keisuke

Proceedings of the IEICE General Conference　2016　(2)　331-331　2016/03/01
Publisher: The Institute of Electronics, Information and Communication Engineers
Ultra-Multilevel Digital Coherent Optical Transmission with a Narrow Linewidth Laser, an Optical Phase-Locked Loop Circuit, and Injection-Locking Scheme

KASAI Keisuke, NAKAZAWA Masataka

The Review of Laser Engineering　44　(2)　106　2016
Publisher: The Laser Society of Japan
DOI： 10.2184/lsj.44.2_106 　

ISSN： 0387-0200

eISSN： 1349-6603

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In recent years, with the aim of keeping up with the rapid increase in transmission capacity, coherent optical transmission employing multi-level modulation formats has been intensively studied. In particular, quadrature amplitude modulation (QAM), in which information is encoded on both the amplitude and phase of the optical carrier, has attracted a lot of attention because of its ability to achieve higher spectral efficiency (SE) than other formats. Indispensable to the realization of ultra-multilevel QAM coherent optical transmission with an extremely high SE are narrow linewidth lasers and a precise optical carrier phase synchronization scheme between the transmitted data and the local oscillator. In this paper, we summarize our recent progress on ultra-multilevel QAM coherent transmission using a homodyne detection method by employing a frequency-stabilized fiber laser as a coherent light source, an optical phase-locked loop circuit, and an injection locking scheme for carrier phase synchronization at the receiver.
CK-3-6 Optical and wireless-integrated next-generation access network based on coherent technologies

Nakazawa Masataka

Proceedings of the Society Conference of IEICE　2015　(1)　"SS-31"-"SS-32"　2015/08/25
Publisher: The Institute of Electronics, Information and Communication Engineers
CK-3-6 Optical and wireless-integrated next-generation access network based on coherent technologies

Nakazawa Masataka

Proceedings of the Society Conference of IEICE　2015　(2)　"SS-31"-"SS-32"　2015/08/25
Publisher: The Institute of Electronics, Information and Communication Engineers
CK-3-6 Optical and wireless-integrated next-generation access network based on coherent technologies

Nakazawa Masataka

Proceedings of the Society Conference of IEICE　2015　(2)　"SS-31"-"SS-32"　2015/08/25
Publisher: The Institute of Electronics, Information and Communication Engineers
B-10-46 2.56 Tbit/s/ch DQPSK Non-Coherent Nyquist Pulse Transmission over 525 km

Harako Koudai, Seya Daiki, Suzuki Daiki, Hirooka Toshihiko, Nakazawa Masataka

Proceedings of the Society Conference of IEICE　2015　(2)　210-210　2015/08/25
Publisher: The Institute of Electronics, Information and Communication Engineers
B-10-43 80 Gbit/s, 256 QAM Coherent Optical Transmission over 150 km with an LD-based Injection-locked Homodyne Receiver

Wang Yixin, Kasai Keisuke, Beppu Shohei, Nakazawa Masataka

Proceedings of the Society Conference of IEICE　2015　(2)　207-207　2015/08/25
Publisher: The Institute of Electronics, Information and Communication Engineers
B-10-45 448 Gbit/s, 32 Gbaud 128 QAM coherent transmission over 150 km with a potential spectral efficiency of 10.7 bit/s/Hz

Kasai Keisuke, Wang Yixin, Otuya David Odeke, Yoshida Masato, Nakazawa Masataka

Proceedings of the Society Conference of IEICE　2015　(2)　209-209　2015/08/25
Publisher: The Institute of Electronics, Information and Communication Engineers
B-10-44 120 Gbil/s polarization-multiplexed 64 QAM digital coherent transmission in a deployed ROADM network

Hirooka Toshihiko, Kasai Keisuke, Wang Yixin, Nakazawa Masataka, Shiraiwa Masaki, Awaji Yoshinari, Wada Naoya

Proceedings of the Society Conference of IEICE　2015　(2)　208-208　2015/08/25
Publisher: The Institute of Electronics, Information and Communication Engineers
B-10-50 1024 QAM, 7-core (60 Gbit/s x 7) fiber transmission over 55 km with an aggregate spectral efficiency of 109 bit/s/Hz

Yoshida Masato, Beppu Shohei, Kasai Keisuke, Hirooka Toshihiko, Nakazawa Masataka

Proceedings of the Society Conference of IEICE　2015　(2)　214-214　2015/08/25
Publisher: The Institute of Electronics, Information and Communication Engineers
B-10-57 QAM quantum noise stream cipher using digital coherent optical transmission

Nakazawa Masataka, Yoshida Masato, Hirooka Toshihiko, Kasai Keisuke

Proceedings of the Society Conference of IEICE　2015　(2)　221-221　2015/08/25
Publisher: The Institute of Electronics, Information and Communication Engineers
BI-3-4 Mode-coupling measurement along an optical fiber for space division multiplexed transmission using a multi-channel OTDR

Nakazawa Masataka

Proceedings of the IEICE General Conference　2015　(2)　"SS-65"-"SS-66"　2015/02/24
Publisher: The Institute of Electronics, Information and Communication Engineers
BI-3-4 Mode-coupling measurement along an optical fiber for space division multiplexed transmission using a multi-channel OTDR

Nakazawa Masataka

Proceedings of the IEICE General Conference　2015　(2)　"SS-65"-"SS-66"　2015/02/24
Publisher: The Institute of Electronics, Information and Communication Engineers
B-10-26 1.92 Tbit/s/ch, 64 QAM coherent Nyquist pulse transmission with a spectral efficiency of 10.6 bit/s/Hz

Otuya David Odeke, Harako Koudai, Kasai Keisuke, Hirooka Toshihiko, Nakazawa Masataka

Proceedings of the IEICE General Conference　2015　(2)　362-362　2015/02/24
Publisher: The Institute of Electronics, Information and Communication Engineers
5G R&D Activities for High Capacity Technologies with Ultra High-Density Multi-Band and Multi-Access Layered Cells

箕輪守彦, 関宏之, 奥村幸彦, 須山聡, 大高明浩, 木村俊二, 中津川征士, 浅野弘明, 市川泰史, 平野幸男, 山尾泰, 安達文幸, 中沢正隆

電子情報通信学会技術研究報告　115　(369(RCS2015 243-279))　2015

ISSN： 0913-5685
Resilient ICT research activities of ROEC at Tohoku University and its cooperation with NICT

NAKAZAWA Masataka

114　(287)　1-6　2014/11/05
Publisher: The Institute of Electronics, Information and Communication Engineers
ISSN： 0913-5685

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The Great East Japan Earthquake revealed various difficulties in information and communication infrastructures in the wake of a devastating disaster, such as transmission link disruption, disabilities in information collection, and lack of messages. It is therefore indispensable to construct disaster-resilient ICT networks to cope with next unpredictable disasters. In this talk, we describe our activities on resilient ICT technologies in Research Organization of Electrical Communication (ROEC) at Tohoku University and cooperation with Resilient ICT Research Center at NICT. In particular, we focus on our recent attempts toward constructing disaster-resilient optical networks.
High-performance TDM demultiplexing of coherent Nyquist pulses using time-domain orthogonality

HARAKO Koudai, OTUYA David Odeke, KASAI Keisuke, HIROOKA Toshihiko, NAKAZAWA Masataka

Technical report of IEICE. OCS　114　(281)　97-100　2014/10/30
Publisher: The Institute of Electronics, Information and Communication Engineers
ISSN： 0913-5685

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We propose a simple and high-performance scheme for demultiplexing coherent Nyquist TDM signals by photo-mixing on a photo-detector with Nyquist LO pulses. This scheme takes advantage of the time-domain orthogonality of Nyquist pulses, which enables high-SNR demultiplexing and homodyne detection simultaneously in spite of a strong overlap with adjacent pulses in the time domain. The feasibility of this scheme is demonstrated through a demultiplexing experiment employing 80 Gbaud, 64 QAM Nyquist pulse OTDM signals. This scheme exhibits excellent demultiplexing performance with a much simpler configuration than a conventional ultrafast all-optical sampling scheme.
B-10-43 2048 QAM (66 Gbit/s) Digital Coherent Optical Transmission over 150 km

Beppu Shohei, Kasai Keisuke, Yoshida Masato, Nakazawa Masataka

Proceedings of the IEICE General Conference　2014　(2)　411-411　2014/03/04
Publisher: The Institute of Electronics, Information and Communication Engineers
B-10-29 High Speed, Low Penalty Optical Demultiplexing Using Nonlinear Optical Loop Mirror With a Nyquist Control Pulse

Seya Daiki, Harako Kodai, Hirooka Toshihiko, Nakazawa Masataka

Proceedings of the IEICE General Conference　2014　(2)　397-397　2014/03/04
Publisher: The Institute of Electronics, Information and Communication Engineers
B-10-28 100 Gbit/s real-time digital coherent transmission over a 32 km multi-mode graded-index fiber

Hirooka Toshihiko, Nakazawa Masataka, Komukai Tetsuro, Sakano Toshikazu

Proceedings of the IEICE General Conference　2014　(2)　396-396　2014/03/04
Publisher: The Institute of Electronics, Information and Communication Engineers
Recent Trends in Multilevel and Multimode Technologies

NAKAZAWA Masataka, KOKUBUN Yasuo

The Journal of the Institute of Electronics, Information, and Communication Engineers　97　(2)　119-123　2014/02
Publisher: The Institute of Electronics, Information and Communication Engineers
ISSN： 0913-5693
災害に強いネットワークと光通信技術—Disaster-resilient Networks and Optical Communication Technologies—特別小特集東北から明るい未来を創るICT技術

中沢正隆

電子情報通信学会誌 = The journal of the Institute of Electronics, Information and Communication Engineers　96　(10)　748-751　2013/10
Publisher: 東京 : 電子情報通信学会
ISSN： 0913-5693

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資料形態 : テキストデータプレーンテキストコレクション : 国立国会図書館デジタルコレクション > デジタル化資料 > 雑誌
A 120 Gbit/s, 64 QAM coherent transmission over 150 km employing an optical voltage controlled oscillator

Wang Yixin, Kasai Keisuke, Omiya Tatsunori, Nakazawa Masataka

Proceedings of the Society Conference of IEICE　2013　(2)　243-243　2013/09/03
Publisher: The Institute of Electronics, Information and Communication Engineers
1.28 Tbit/s/ch optical Nyquist transmission over 525 km with substantial PMD tolerance

Harako Kodai, Seya Daiki, Hirooka Toshihiko, Nakazawa Masataka

Proceedings of the Society Conference of IEICE　2013　(2)　241-241　2013/09/03
Publisher: The Institute of Electronics, Information and Communication Engineers
光多値化技術とさらなる周波数利用効率向上に向けて (特集光ファイバー通信の新たなブレークスルーへ向けて)

中沢正隆, 廣岡俊彦, 吉田真人

O plus E : Optics・Electronics　35　(8)　836-841　2013/08
Publisher: アドコム・メディア
ISSN： 0911-5943
B-10-26 AStudy on the Optimization of 7-core Multicore Erbium-doped Fiber Optical Amplifier

Tsuchida Yukihiro, Maeda Koichi, Watanabe Kengo, Ito Toshiharu, Fukuchi Kiyoshi, Yoshida Masato, Mimura Yu, Sugizaki Ryuichi, Nakazawa Masataka

Proceedings of the IEICE General Conference　2013　(2)　357-357　2013/03/05
Publisher: The Institute of Electronics, Information and Communication Engineers
TK-3-7 Optical Transmission Technologies for Enhancing the Resilience of Information and Communication Networks

Morita Itsuro, Yoshikane Noboru, Tsuritani Takehiro, Hirooka Toshihiko, Yoshida Masato, Nakazawa Masataka

Proceedings of the IEICE General Conference　2013　(2)　"SSS-30"-"SSS-31"　2013/03/05
Publisher: The Institute of Electronics, Information and Communication Engineers
ペタビットを目指すマルチコア光ファイバ技術 III 多値伝送実現に向けたマルチコア光ファイバの大コア化とクロストーク評価技術

今村勝徳, 杉崎隆一, 吉田真人, 中沢正隆

ITUジャーナル(Web)　43　(11)　2013

ISSN： 2434-9712
B-10-90 An LD-based optical phase-locked loop circuit by using an optical voltage controlled oscillator

Kasai Keisuke, Wang Yixin, Nakazawa Masataka

Proceedings of the Society Conference of IEICE　2012　(2)　272　2012/08/28
Publisher: The Institute of Electronics, Information and Communication Engineers
B-10-67 1024 QAM (60 Gbit/s) optical coherent transmission over 150 km

Koizumi Yuki, Toyoda Kazushi, Yoshida Masato, Nakazawa Masataka

Proceedings of the Society Conference of IEICE　2012　(2)　249-249　2012/08/28
Publisher: The Institute of Electronics, Information and Communication Engineers
B-10-66 Highly dispersion-tolerant 160 Gbaud optical Nyquist pulse TDM transmission over 525 km

Hirooka Toshihiko, Ruan Peng, Guan Pengyu, Nakazawa Masataka

Proceedings of the Society Conference of IEICE　2012　(2)　248-248　2012/08/28
Publisher: The Institute of Electronics, Information and Communication Engineers
B-10-90 An LD-based optical phase-locked loop circuit by using an optical voltage controlled oscillator

Kasai Keisuke, Wang Yixin, Nakazawa Masataka

Proceedings of the Society Conference of IEICE　2012　(2)　272-272　2012/08/28
Publisher: The Institute of Electronics, Information and Communication Engineers
B-10-34 Marked performance improvement of 256 QAM transmission using a digital back-propagation method

Toyoda Kazushi, Koizumi Yuki, Omiya Tatsunori, Yoshida Masato, Hirooka Toshihiko, Nakazawa Masataka

Proceedings of the Society Conference of IEICE　2012　(2)　216-216　2012/08/28
Publisher: The Institute of Electronics, Information and Communication Engineers
B-10-35 Performance improvement of 512 QAM transmission using frequency-domain equalization

Omiya Tatsunori, Koizumi Yuki, Toyoda Kazushi, Yoshida Masato, Nakazawa Masataka

Proceedings of the Society Conference of IEICE　2012　(2)　217-217　2012/08/28
Publisher: The Institute of Electronics, Information and Communication Engineers
B-10-62 1.1 μm, 160 Gbit/s OTDM transmission over 30 km

Koizumi Kengo, Hirooka Toshihiko, Yoshida Masato, Nakazawa Masataka

Proceedings of the Society Conference of IEICE　2012　(2)　244-244　2012/08/28
Publisher: The Institute of Electronics, Information and Communication Engineers
Performance improvement of optical frequency stabilized Cs optical atomic clock

TOKUHIRA Kazunari, SUZUKI Fumitaka, YOSHIDA Masato, NAKAZAWA Masataka

IEICE technical report. Component parts and materials　112　(182)　21-25　2012/08/16
Publisher: The Institute of Electronics, Information and Communication Engineers
ISSN： 0913-5685

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We have proposed a Cs optical atomic clock, which generates a standard microwave clock signal with an optical pulse. The clock source uses a regenerative mode-locked fiber laser (MLFL) as a microwave oscillator and an optically pumped Cs gas cell as a frequency standard. In this report, the output pulse width was shortened from 7.1 to 3.4 ps by employing a phase modulator instead of an intensity modulator as a mode-locker. The optical frequency stability for an averaging time of 100 s was also improved from 1.8 x 10^<-11> to 6.3 x 10^<-12> by precisely controlling the laser cavity temperature.
1.07μm passively mode-locked ytterbium-doped fiber laser with SWNT/PMMA saturable absorber

YOSHIDA Masato, HORI Yuichiro, HIROOKA Toshihiko, NAKAZAWA Masataka

IEICE technical report. Component parts and materials　112　(182)　83-86　2012/08/16
Publisher: The Institute of Electronics, Information and Communication Engineers
ISSN： 0913-5685

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Single-wall carbon nanotubes (SWNT) have received considerable attention as a nonlinear optical material for ultrashort lasers and optical switch devices because of their attractive features such as ultrafast saturable absorption (SA) effects with a recovery time of faster than 1 ps. The SA wavelength depends on the tube diameter. We previously reported an SWNT polymer material that used polymethylmethacrylate (PMMA) and applied it to a passively mode-locked Er fiber laser for 171 fs pulse generation at 1.55 μm. In this report, we describe a mode-locked Yb-doped fiber laser for femtosecond pulse generation at 1.1 μm realized by using an SWNT/PMMA wafer in the cavity. By optimizing the cavity configuration as a dispersion-managed soliton laser, we obtained a 543 fs, 15.1 MHz pulse train.
Increase of Output Power of Passively Mode-Locked Fiber Laser with a SWNT

ONO Takato, HORI Yuichiro, YOSHIDA Masato, HIROOKA Toshihiko, NAKAZAWA Masataka, MATA Junji, TSUKAMOTO Jun

IEICE technical report. Component parts and materials　112　(182)　87-90　2012/08/16
Publisher: The Institute of Electronics, Information and Communication Engineers
ISSN： 0913-5685

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We have demonstrated a passively mode-locked fiber laser with SWNT-based saturable absorbers made by uniformly dispersing SWNTs into polymer such as poly methyl methacrylate, or by depositing SWNTs on the optical fiber end. However, the output power of the lasers is limited to less than 10 mW due to relatively low tolerance to optical damage of these SWNT-based saturable absorbers. In this work, we fabricated a SWNT saturable absorber with a substantial increase in the optical damage threshold by sealing SWNT with siloxane which has a high heat resistance. By installing this saturable absorber in a passively mode-locked fiber laser, a 31 mW, 280 fs ultrashort pulse was successfully generated.
Performance improvement of optical frequency stabilized Cs optical atomic clock

TOKUHIRA Kazunari, SUZUKI Fumitaka, YOSHIDA Masato, NAKAZAWA Masataka

IEICE technical report. Reliability　112　(180)　21-25　2012/08/16
Publisher: The Institute of Electronics, Information and Communication Engineers
ISSN： 0913-5685

More details Close

We have proposed a Cs optical atomic clock, which generates a standard microwave clock signal with an optical pulse. The clock source uses a regenerative mode-locked fiber laser (MLFL) as a microwave oscillator and an optically pumped Cs gas cell as a frequency standard. In this report, the output pulse width was shortened from 7.1 to 3.4 ps by employing a phase modulator instead of an intensity modulator as a mode-locker. The optical frequency stability for an averaging time of 100 s was also improved from 1.8 x 10^<-11> to 6.3 x 10^<-12> by precisely controlling the laser cavity temperature.
1.07μm passively mode-locked ytterbium-doped fiber laser with SWNT/PMMA saturable absorber

YOSHIDA Masato, HORI Yuichiro, HIROOKA Toshihiko, NAKAZAWA Masataka

IEICE technical report. Reliability　112　(180)　83-86　2012/08/16
Publisher: The Institute of Electronics, Information and Communication Engineers
ISSN： 0913-5685

More details Close

Single-wall carbon nanotubes (SWNT) have received considerable attention as a nonlinear optical material for ultrashort lasers and optical switch devices because of their attractive features such as ultrafast saturable absorption (SA) effects with a recovery time of faster than 1 ps. The SA wavelength depends on the tube diameter. We previously reported an SWNT polymer material that used polymethylmethacrylate (PMMA) and applied it to a passively mode-locked Er fiber laser for 171 fs pulse generation at 1.55 μm. In this report, we describe a mode-locked Yb-doped fiber laser for femtosecond pulse generation at 1.1 μm realized by using an SWNT/PMMA wafer in the cavity. By optimizing the cavity configuration as a dispersion-managed soliton laser, we obtained a 543 fs, 15.1 MHz pulse train.
Increase of Output Power of Passively Mode-Locked Fiber Laser with a SWNT

ONO Takato, HORI Yuichiro, YOSHIDA Masato, HIROOKA Toshihiko, NAKAZAWA Masataka, MATA Junji, TSUKAMOTO Jun

IEICE technical report. Reliability　112　(180)　87-90　2012/08/16
Publisher: The Institute of Electronics, Information and Communication Engineers
ISSN： 0913-5685

More details Close

We have demonstrated a passively mode-locked fiber laser with SWNT-based saturable absorbers made by uniformly dispersing SWNTs into polymer such as poly methyl methacrylate, or by depositing SWNTs on the optical fiber end. However, the output power of the lasers is limited to less than 10 mW due to relatively low tolerance to optical damage of these SWNT-based saturable absorbers. In this work, we fabricated a SWNT saturable absorber with a substantial increase in the optical damage threshold by sealing SWNT with siloxane which has a high heat resistance. By installing this saturable absorber in a passively mode-locked fiber laser, a 31 mW, 280 fs ultrashort pulse was successfully generated.
Performance improvement of optical frequency stabilized Cs optical atomic clock

TOKUHIRA Kazunari, SUZUKI Fumitaka, YOSHIDA Masato, NAKAZAWA Masataka

IEICE technical report. EMD　112　(181)　21-25　2012/08/16
Publisher: The Institute of Electronics, Information and Communication Engineers
ISSN： 0913-5685

More details Close

We have proposed a Cs optical atomic clock, which generates a standard microwave clock signal with an optical pulse. The clock source uses a regenerative mode-locked fiber laser (MLFL) as a microwave oscillator and an optically pumped Cs gas cell as a frequency standard. In this report, the output pulse width was shortened from 7.1 to 3.4 ps by employing a phase modulator instead of an intensity modulator as a mode-locker. The optical frequency stability for an averaging time of 100 s was also improved from 1.8 x 10^<-11> to 6.3 x 10^<-12> by precisely controlling the laser cavity temperature.
Performance improvement of optical frequency stabilized Cs optical atomic clock

TOKUHIRA Kazunari, SUZUKI Fumitaka, YOSHIDA Masato, NAKAZAWA Masataka

Technical report of IEICE. OPE　112　(183)　21-25　2012/08/16
Publisher: The Institute of Electronics, Information and Communication Engineers
ISSN： 0913-5685

More details Close

We have proposed a Cs optical atomic clock, which generates a standard microwave clock signal with an optical pulse. The clock source uses a regenerative mode-locked fiber laser (MLFL) as a microwave oscillator and an optically pumped Cs gas cell as a frequency standard. In this report, the output pulse width was shortened from 7.1 to 3.4 ps by employing a phase modulator instead of an intensity modulator as a mode-locker. The optical frequency stability for an averaging time of 100 s was also improved from 1.8 x 10^<-11> to 6.3 x 10^<-12> by precisely controlling the laser cavity temperature.
1.07μm passively mode-locked ytterbium-doped fiber laser with SWNT/PMMA saturable absorber

YOSHIDA Masato, HORI Yuichiro, HIROOKA Toshihiko, NAKAZAWA Masataka

IEICE technical report. EMD　112　(181)　83-86　2012/08/16
Publisher: The Institute of Electronics, Information and Communication Engineers
ISSN： 0913-5685

More details Close

Single-wall carbon nanotubes (SWNT) have received considerable attention as a nonlinear optical material for ultrashort lasers and optical switch devices because of their attractive features such as ultrafast saturable absorption (SA) effects with a recovery time of faster than 1 ps. The SA wavelength depends on the tube diameter. We previously reported an SWNT polymer material that used polymethylmethacrylate (PMMA) and applied it to a passively mode-locked Er fiber laser for 171 fs pulse generation at 1.55 μm. In this report, we describe a mode-locked Yb-doped fiber laser for femtosecond pulse generation at 1.1 μm realized by using an SWNT/PMMA wafer in the cavity. By optimizing the cavity configuration as a dispersion-managed soliton laser, we obtained a 543 fs, 15.1 MHz pulse train.
Increase of Output Power of Passively Mode-Locked Fiber Laser with a SWNT

ONO Takato, HORI Yuichiro, YOSHIDA Masato, HIROOKA Toshihiko, NAKAZAWA Masataka, MATA Junji, TSUKAMOTO Jun

IEICE technical report. EMD　112　(181)　87-90　2012/08/16
Publisher: The Institute of Electronics, Information and Communication Engineers
ISSN： 0913-5685

More details Close

We have demonstrated a passively mode-locked fiber laser with SWNT-based saturable absorbers made by uniformly dispersing SWNTs into polymer such as poly methyl methacrylate, or by depositing SWNTs on the optical fiber end. However, the output power of the lasers is limited to less than 10 mW due to relatively low tolerance to optical damage of these SWNT-based saturable absorbers. In this work, we fabricated a SWNT saturable absorber with a substantial increase in the optical damage threshold by sealing SWNT with siloxane which has a high heat resistance. By installing this saturable absorber in a passively mode-locked fiber laser, a 31 mW, 280 fs ultrashort pulse was successfully generated.
Performance improvement of optical frequency stabilized Cs optical atomic clock

TOKUHIRA Kazunari, SUZUKI Fumitaka, YOSHIDA Masato, NAKAZAWA Masataka

Technical report of IEICE. LQE　112　(184)　21-25　2012/08/16
Publisher: The Institute of Electronics, Information and Communication Engineers
ISSN： 0913-5685

More details Close

We have proposed a Cs optical atomic clock, which generates a standard microwave clock signal with an optical pulse. The clock source uses a regenerative mode-locked fiber laser (MLFL) as a microwave oscillator and an optically pumped Cs gas cell as a frequency standard. In this report, the output pulse width was shortened from 7.1 to 3.4 ps by employing a phase modulator instead of an intensity modulator as a mode-locker. The optical frequency stability for an averaging time of 100 s was also improved from 1.8 x 10^<-11> to 6.3 x 10^<-12> by precisely controlling the laser cavity temperature.
1.07μm passively mode-locked ytterbium-doped fiber laser with SWNT/PMMA saturable absorber

YOSHIDA Masato, HORI Yuichiro, HIROOKA Toshihiko, NAKAZAWA Masataka

Technical report of IEICE. OPE　112　(183)　83-86　2012/08/16
Publisher: The Institute of Electronics, Information and Communication Engineers
ISSN： 0913-5685

More details Close

Single-wall carbon nanotubes (SWNT) have received considerable attention as a nonlinear optical material for ultrashort lasers and optical switch devices because of their attractive features such as ultrafast saturable absorption (SA) effects with a recovery time of faster than 1 ps. The SA wavelength depends on the tube diameter. We previously reported an SWNT polymer material that used polymethylmethacrylate (PMMA) and applied it to a passively mode-locked Er fiber laser for 171 fs pulse generation at 1.55 μm. In this report, we describe a mode-locked Yb-doped fiber laser for femtosecond pulse generation at 1.1 μm realized by using an SWNT/PMMA wafer in the cavity. By optimizing the cavity configuration as a dispersion-managed soliton laser, we obtained a 543 fs, 15.1 MHz pulse train.
Increase of Output Power of Passively Mode-Locked Fiber Laser with a SWNT

ONO Takato, HORI Yuichiro, YOSHIDA Masato, HIROOKA Toshihiko, NAKAZAWA Masataka, MATA Junji, TSUKAMOTO Jun

Technical report of IEICE. OPE　112　(183)　87-90　2012/08/16
Publisher: The Institute of Electronics, Information and Communication Engineers
ISSN： 0913-5685

More details Close

We have demonstrated a passively mode-locked fiber laser with SWNT-based saturable absorbers made by uniformly dispersing SWNTs into polymer such as poly methyl methacrylate, or by depositing SWNTs on the optical fiber end. However, the output power of the lasers is limited to less than 10 mW due to relatively low tolerance to optical damage of these SWNT-based saturable absorbers. In this work, we fabricated a SWNT saturable absorber with a substantial increase in the optical damage threshold by sealing SWNT with siloxane which has a high heat resistance. By installing this saturable absorber in a passively mode-locked fiber laser, a 31 mW, 280 fs ultrashort pulse was successfully generated.
1.07μm passively mode-locked ytterbium-doped fiber laser with SWNT/PMMA saturable absorber

YOSHIDA Masato, HORI Yuichiro, HIROOKA Toshihiko, NAKAZAWA Masataka

Technical report of IEICE. LQE　112　(184)　83-86　2012/08/16
Publisher: The Institute of Electronics, Information and Communication Engineers
ISSN： 0913-5685

More details Close

Single-wall carbon nanotubes (SWNT) have received considerable attention as a nonlinear optical material for ultrashort lasers and optical switch devices because of their attractive features such as ultrafast saturable absorption (SA) effects with a recovery time of faster than 1 ps. The SA wavelength depends on the tube diameter. We previously reported an SWNT polymer material that used polymethylmethacrylate (PMMA) and applied it to a passively mode-locked Er fiber laser for 171 fs pulse generation at 1.55 μm. In this report, we describe a mode-locked Yb-doped fiber laser for femtosecond pulse generation at 1.1 μm realized by using an SWNT/PMMA wafer in the cavity. By optimizing the cavity configuration as a dispersion-managed soliton laser, we obtained a 543 fs, 15.1 MHz pulse train.
Increase of Output Power of Passively Mode-Locked Fiber Laser with a SWNT

ONO Takato, HORI Yuichiro, YOSHIDA Masato, HIROOKA Toshihiko, NAKAZAWA Masataka, MATA Junji, TSUKAMOTO Jun

Technical report of IEICE. LQE　112　(184)　87-90　2012/08/16
Publisher: The Institute of Electronics, Information and Communication Engineers
ISSN： 0913-5685

More details Close

We have demonstrated a passively mode-locked fiber laser with SWNT-based saturable absorbers made by uniformly dispersing SWNTs into polymer such as poly methyl methacrylate, or by depositing SWNTs on the optical fiber end. However, the output power of the lasers is limited to less than 10 mW due to relatively low tolerance to optical damage of these SWNT-based saturable absorbers. In this work, we fabricated a SWNT saturable absorber with a substantial increase in the optical damage threshold by sealing SWNT with siloxane which has a high heat resistance. By installing this saturable absorber in a passively mode-locked fiber laser, a 31 mW, 280 fs ultrashort pulse was successfully generated.
32 RZ/QAM coherent optical transmission employing an RZ-CW conversion technique

KASAI Keisuke, OTUYA David Odeke, YOSHIDA Masato, HIROOKA Toshihiko, NAKAZAWA Masataka

Technical report of IEICE. OCS　112　(152)　13-18　2012/07/19
Publisher: The Institute of Electronics, Information and Communication Engineers
ISSN： 0913-5685

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Coherent optical time division multiplexing (OTDM) transmission with a multi-level modulation format has attracted a lot of attention as a ultra-high speed and highly spectral-efficient optical transmission system. However, in the conventional coherent OTDM, it is difficult to demodulate an ultra-high speed, multi-level RZ data signal with a high signal to noise ratio due to input optical power limitation of coherent detection circuits. Recently, we proposed a demodulation scheme by using an RZ-CW conversion scheme in a coherent receiver, in which the transmitted coherent RZ data are OTDM demultiplexed and converted into a data signal on a CW carrier. In this paper, we demonstrate an advantage of the scheme with 10 Gsymbol/s, 4- and 8-OTDM 32 RZ/QAM demodulation experiments. Furthermore, we have successfully transmitted a polarization multiplexed, 10 Gsymbol/s, 32 RZ/QAM (800 Git/s) data signal over 225 km by using this conversion scheme.
Demultiplexing of 160Gbit/s OTDM signal using a nonlinear optical loop mirror at 1.1μm

KOIZUMI Kengo, HIROOKA Toshihiko, YOSHIDA Masato, NAKAZAWA Masataka

Technical report of IEICE. OCS　112　(86)　47-52　2012/06/14
Publisher: The Institute of Electronics, Information and Communication Engineers
ISSN： 0913-5685

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With the increasing demand for ultrahigh capacity optical networks, it has been increasingly important to exploit new transmission bandwidths beyond the 1.55 and 1.31μm bands. The 1.1μm region is expected to provide an ultrawide transmission band because a wideband ytterbium (Yb)-doped fiber amplifiers (YDFA) are available. In this talk, we describe a multiplexer and demultiplexer using a nonlinear optical loop mirror (NOLM), and demonstrate the generation and demultiplexing of a 160 Gbit/s optical time-division multiplexed (OTDM) signal using a 10 GHz mode-locked Yb fiber laser in the 1.1μm wavelength region.
Depolarization-Induced Crosstalk in Polarization-Multiplexed Transmission and Its Impact on Ultrahigh-Speed Optical Transmission

HIROOKA Toshihiko, HARAKO Koudai, GUAN Pengyu, NAKAZAWA Masataka

Technical report of IEICE. OCS　112　(42)　1-4　2012/05/11
Publisher: The Institute of Electronics, Information and Communication Engineers
ISSN： 0913-5685

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Ultrashort optical pulses such as used in a single-channel Terabit/s OTDM transmission suffers from significant transmission impairments due to second-order PMD, i.e., signal depolarization due to frequency dependence of a principal state of polarization, even when the first-order PMD is completely compensated. In particular, in polarization-multiplexed transmission, depolarization leads to a complicated form of inter-polarization crosstalk, which prevents one from complete separation of the two channels. In this paper, we shall present an analytical expression and experimental demonstration of depolarization-induced crosstalk in polarization-multiplexed transmission caused by second-order PMD. It is found that the crosstalk depends on the fourth power of the bandwidth and the square of distance.
B-10-34 Ultrahigh-speed orthogonal TDM transmission with an optical Nyquist pulse train

Nakazawa Masataka, Hirooka Toshihiko, Ruan Peng, Guan Pengyu

Proceedings of the IEICE General Conference　2012　(2)　357-357　2012/03/06
Publisher: The Institute of Electronics, Information and Communication Engineers
B-10-33 400 Gbit/s Frequency-Division-Multiplexed and Polarization-Multiplexed 256 QAM-OFDM Transmission over 400 km

Omiya Tatsunori, Toyoda Kazushi, Yoshida Masato, Nakazawa Masataka

Proceedings of the IEICE General Conference　2012　(2)　356-356　2012/03/06
Publisher: The Institute of Electronics, Information and Communication Engineers
B-10-54 Single-channel 800 Gbit/s, 32 RZ/QAM coherent transmission employing an RZ-CW conversion technique

Kasai Keisuke, Odeke Otuya David, Yoshida Masato, Hirooka Toshihiko, Nakazawa Masataka

Proceedings of the IEICE General Conference　2012　(2)　377-377　2012/03/06
Publisher: The Institute of Electronics, Information and Communication Engineers
B-10-70 Demultiplexing of 160 Gbit/s OTDM signal using a nonlinear optical loop mirror at 1.1μm

Koizumi Kengo, Hirooka Toshihiko, Yoshida Masato, Nakazawa Masataka

Proceedings of the IEICE General Conference　2012　(2)　393-393　2012/03/06
Publisher: The Institute of Electronics, Information and Communication Engineers
One Year after the Great East Japan Earthquake Disaster

NAKAZAWA Masataka

The Journal of the Institute of Electronics, Information, and Communication Engineers　95　(3)　188-194　2012/03/01
Publisher: The Institute of Electronics, Information and Communication Engineers
ISSN： 0913-5693
エクサビット情報社会に向けて飛躍する革新的光通信技術 (特集エクサへの挑戦--超大容量光ファイバー通信技術の最新動向)

中沢正隆

O plus E　33　(9)　907-913　2011/09
Publisher: アドコム・メディア
ISSN： 0911-5943
B-10-50 120 Gbit/s, 64 QAM Coherent Transmission over 150 km with OPLL Employing Narrow Linewidth LDs

Wang Yixin, Kasai Keisuke, Nakazawa Masataka

Proceedings of the Society Conference of IEICE　2011　(2)　263-263　2011/08/30
Publisher: The Institute of Electronics, Information and Communication Engineers
B-10-49 Comparison between Polarization-Multiplexed DPSK and Single-Polarization DQPSK in 1.28Tbit/s/ch-525 km Transmission

Tomiyama Yutaro, Harako Koudai, Guan Pengyu, Hirooka Toshihiko, Nakazawa Masataka

Proceedings of the Society Conference of IEICE　2011　(2)　262-262　2011/08/30
Publisher: The Institute of Electronics, Information and Communication Engineers
BI-7-8 512 QAM ultra-multilevel digital coherent optical transmission

Koizumi Yuki, Toyoda Kazushi, Yoshida Masato, Hirooka Toshihiko, Nakazawa Masataka

Proceedings of the Society Conference of IEICE　2011　(1)　"SS-67"-"SS-68"　2011/08/30
Publisher: The Institute of Electronics, Information and Communication Engineers
Oscillation characteristics of an ^<13>C_2H_2 frequency-stabilized λ/4-shifted DFB LD with an external fiber ring cavity

KASAI Keisuke, NAKAZAWA Masataka

IEICE technical report　111　(185)　49-52　2011/08/18
Publisher: The Institute of Electronics, Information and Communication Engineers
ISSN： 0913-5685

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We demonstrate frequency stabilization of a λ/4-shifted distributed feedback laser diode (DFB LD) with an external fiber ring cavity to an ^<13>C_2H_2 (acetylene) linear absorption line. By employing a feedback control of the λ/4-shifted DFB passband to track one Fabry-Perot mode associated with the fiber ring cavity, we have successfully tuned an oscillation frequency over 1.2 GHz without mode-hopping. The optical frequency was stabilized to a ^<13>C_2H_2 absorption line with an external frequency modulation scheme, which realizes an FM-eliminated output beam. The frequency stabilities reached as high as 1.4×10^<-10> for τ=1 s and 1.3×10^<-11> for τ=100 s. Furthermore, a linewidth of 2.6 kHz and a relative intensity noise of less than -135 dB/Hz were simultaneously achieved.
Development of FPGA-based real-time receiver for 64 QAM coherent signals

YOSHIDA Masato, OMIYA Tatsunori, KASAI Keisuke, NAKAZAWA Masataka

IEICE technical report　111　(122)　7-12　2011/07/04
Publisher: The Institute of Electronics, Information and Communication Engineers
ISSN： 0913-5685

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We demonstrate the first real-time coherent optical transmission of a 1 Gsymbol/s, 64 QAM data signal. The real-time coherent receiver consists of four 1 GS/s analog-to-digital converters (ADC) and a field-programmable gate array (FPGA) implementation. The bit error rate (BER) performance obtained with the real-time receiver is the same as that obtained with an off-line digital signal processor (DSP). This result indicates that the phase of the IF signal and the data clock timing are precisely controlled without any DSP compensations in our real-time coherent transmission system. As a result, an error free performance (BER < 1 x 10<-12>) has been achieved under a back-to-back condition.
Frequency Division Multiplexing 64 QAM-OFDM (420 Gb/s) transmission over 160 km

OMIYA Tatsunori, TOYODA Kazushi, KASAI Keisuke, YOSHIDA Masato, NAKAZAWA Masataka

IEICE technical report　111　(122)　93-98　2011/07/04
Publisher: The Institute of Electronics, Information and Communication Engineers
ISSN： 0913-5685

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We have demonstrated 64QAM-OFDM coherent optical transmission with a C_2H_2 frequency-stabilized fiber laser and an optical phase-locked loop (OPLL) circuit. In this report, we describe experimental result of 7ch-frequency-division-multiplexed and polarization-multiplexed 5 Gsymbol/s 64 QAM-OFDM (420 Gb/s) transmission. After 160 km transmission, we applied compensation for impairments due to fiber nonlinearity by using back propagation method and improved the bit error rate (BER) performance. As a result, a BER below the forward error correction (FEC) limit and a spectral efficiency as high as 10.4 b/s/Hz were successfully demonstrated.
C-3-17 Femtosecond fiber soliton lasers using a CNT saturable absorber

Hori Yuichiro, Nakazawa Masataka

Proceedings of the IEICE General Conference　2011　(1)　192-192　2011/02/28
Publisher: The Institute of Electronics, Information and Communication Engineers
B-10-27 PMD-Induced Crosstalk in the Presence of PDL in a Polarization-Multiplexed Ultrahigh-Speed Transmission

Hirooka Toshihiko, Hirano Toshiyuki, Guan Pengyu, Nakazawa Masataka

Proceedings of the IEICE General Conference　2011　(2)　336-336　2011/02/28
Publisher: The Institute of Electronics, Information and Communication Engineers
B-10-82 640 Gbit/s Clock Recovery Using Time-Domain Optical Fourier Transformation and Narrow-Band Optical Filter

Guan Pengyu, Mulvad Hans Christian Hansen, Kasai Keisuke, Hirooka Toshihiko, Nakazawa Masataka

Proceedings of the IEICE General Conference　2011　(2)　391-391　2011/02/28
Publisher: The Institute of Electronics, Information and Communication Engineers
B-10-39 512 QAM (54 Gbit/s) coherent optical transmission over 150 km

Okamoto Seiji, Toyoda Kazushi, Omiya Tatsunori, Kasai Keisuke, Yoshida Masato, Nakazawa Masataka

Proceedings of the IEICE General Conference　2011　(2)　348-348　2011/02/28
Publisher: The Institute of Electronics, Information and Communication Engineers
Special Section on Extremely Advanced Optical Transmission Technologies and Transmission Optical Fiber Technologies towards Exabit Era FOREWORD

Masataka Nakazawa

IEICE TRANSACTIONS ON COMMUNICATIONS　E94B　(2)　375-375　2011/02

ISSN： 0916-8516

eISSN： 1745-1345
Performance improvement of 10Gsymbol/s, 64 QAM coherent optical transmission by using back propagation method of nonlinear Schrodinger equation

TOYODA Kazushi, OKAMOTO Seiji, OMIYA Tatsunori, YOSHIDA Masato, HIROOKA Toshihiko, NAKAZAWA Masataka

IEICE technical report　110　(392)　67-72　2011/01/20
Publisher: The Institute of Electronics, Information and Communication Engineers
ISSN： 0913-5685

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We have demonstrated 64〜512 QAM coherent optical transmission using a C_2H_2 frequency-stabilized fiber laser and an OPLL circuit. In such a ultra multi-level transmission, compensation for impairments due to fiber dispersion and nonlinearity plays a very important role. As a highly precise compensation scheme, a back propagation method of the nonlinear Schrodinger equation has been proposed. We applied this scheme to a single-polarization, 10 Gsymbol/s, 64 QAM transmission and demonstrated the impairment compensation both numerically and experimentally.
C-4-21 A femtosecond fiber soliton laser at 1.1 μm band using SWNT-coated polyimide film as a saturable absorber

Hori Yuichiro, Shohda Fumio, Nakazawa Masataka, Mata Junji, Tsukamoto Jun

Proceedings of the Society Conference of IEICE　2010　(1)　211-211　2010/08/31
Publisher: The Institute of Electronics, Information and Communication Engineers
B-10-79 Performance improvement of 10 Gsymbol/s, 64QAM coherent optical transmission by using back propagation method of nonlinear Schrodinger equation

Toyoda Kazushi, Okamoto Seiji, Omiya Tatsunori, Yoshida Masato, Hirooka Toshihiko, Nakazawa Masataka

Proceedings of the Society Conference of IEICE　2010　(2)　266-266　2010/08/31
Publisher: The Institute of Electronics, Information and Communication Engineers
Single-channel 400Gbit/s, OTDM-32 RZ/QAM coherent transmission over 225km

KASAI Keisuke, OMIYA Tatsunori, GUAN Pengyu, YOSHIDA Masato, HIROOKA Toshihiko, NAKAZAWA Masataka

IEICE technical report　110　(94)　1-6　2010/06/17
Publisher: The Institute of Electronics, Information and Communication Engineers
ISSN： 0913-5685

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Coherent optical time division multiplexing (OTDM) transmission with a multi-level modulation format based on digital signal processing (DSP) has attracted a lot of attention with a view to expanding the capacity per channel of wavelength division multiplexing (WDM) transmission systems. This transmission system can overcome the speed and bandwidth limitations of electrical components such as A/D and D/A converters and realize ultrahigh-speed coherent transmission by using a multi-level amplitude and phase-modulated coherent RZ pulse and the OTDM. However, in a conventional coherent OTDM system, the optical phase between an RZ data pulse and a local oscillator are not phase-locked. Therefore, it is difficult to realize a coherent OTDM transmission with high multiplicity. In this work, we demonstrated a multi-level coherent OTDM transmission with a high-precision optical phase-locked loop (OPLL) technique by using optical comb generation circuits. 400 Gbit/s data (polarization-multiplexed, 10 Gsymbol/s, 4-OTDM 32 RZ/QAM) were successfully transmitted over 225 km with a bit error rate performance below the forward error correction (FEC) limit. We also realized a 320 Gbit/s-450 km transmission with an OTDM 16 RZ/QAM scheme.
Advances in information communication technology based on lasers Peer-reviewed

NAKAZAWA Masataka

Oyo Buturi　79　(6)　508-516　2010/06/10
Publisher: The Japan Society of Applied Physics
DOI： 10.11470/oubutsu.79.6_508 　

ISSN： 0369-8009

eISSN： 2188-2290

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This paper reviews 50 years of advances in laser-based information communication technology(ICT), and mainly focuses on optical fiber communication. The advances are classified into three.
CS-6-3 Frequency-stabilized lasers and an optical phase-lock technique for ultra-multilevel coherent transmission

Kasai Keisuke, Nakazawa Masataka

Proceedings of the IEICE General Conference　2010　(2)　"S-33"-"S-34"　2010/03/02
Publisher: The Institute of Electronics, Information and Communication Engineers
CS-6-2 Ultra-Multilevel Coherent Optical Fiber Transmission Approaching the Shannon Limit

Nakazawa Masataka

Proceedings of the IEICE General Conference　2010　(2)　"S-31"-"S-32"　2010/03/02
Publisher: The Institute of Electronics, Information and Communication Engineers
CS-6-3 Frequency-stabilized lasers and an optical phase-lock technique for ultra-multilevel coherent transmission

Kasai Keisuke, Nakazawa Masataka

Proceedings of the IEICE General Conference　2010　(2)　"S-33"-"S-34"　2010/03/02
Publisher: The Institute of Electronics, Information and Communication Engineers
B-10-89 640Gbit/s/channel-525km single-polarization DPSK transmission with ultrafast time-domain optical Fourier transformation circuit

Hirano Toshiyuki, Guan Pengyu, Hirooka Toshihiko, Nakazawa Masataka

Proceedings of the IEICE General Conference　2010　(2)　427-427　2010/03/02
Publisher: The Institute of Electronics, Information and Communication Engineers
B-10-62 Optical phase-locked loop for coherent OTDM transmission with an optical comb technique

Yoshida Masato, Kasai Keisuke, Omiya Tatsunori, Guan Pengyu, Hirooka Toshihiko, Nakazawa Masataka

Proceedings of the IEICE General Conference　2010　(2)　400-400　2010/03/02
Publisher: The Institute of Electronics, Information and Communication Engineers
B-10-82 Single-channel 400Gbit/s, OTDM-32 RZ/QAM coherent transmission over 225 km

Kasai Keisuke, Omiya Tatsunori, Guan Pengyu, Yoshida Masato, Hirooka Toshihiko, Nakazawa Masataka

Proceedings of the IEICE General Conference　2010　(2)　420-420　2010/03/02
Publisher: The Institute of Electronics, Information and Communication Engineers
B-10-83 10 Gsymbol/s, 128 QAM (140 Gbit/s) coherent optical transmission over 150km

Okamoto Seiji, Omiya Tatsunori, Kasai Keisuke, Yoshida Masato, Nakazawa Masataka

Proceedings of the IEICE General Conference　2010　(2)　421-421　2010/03/02
Publisher: The Institute of Electronics, Information and Communication Engineers
B-10-84 256 QAM (64 Gbit/s) coherent optical transmission over 160km

Nakazawa Masataka, Okamoto Seiji, Omiya Tatsunori, Kasai Keisuke, Yoshida Masato

Proceedings of the IEICE General Conference　2010　(2)　422-422　2010/03/02
Publisher: The Institute of Electronics, Information and Communication Engineers
C-4-1 A 10GHz opto-electronic oscillator at 1.1μm using a single-mode VCSEL and a photonic crystal fiber

Koizumi Kengo, Yoshida Masato, Nakazawa Masataka

Proceedings of the IEICE General Conference　2010　(1)　252-252　2010/03/02
Publisher: The Institute of Electronics, Information and Communication Engineers
Challenging limitations of optical communication infrastructure

M. Nakazawa

New Breeze　22　(1)　3-4　2010/01
B-10-36 320 Gbit/s/ch WDM Transmission over 525 km Using Time-domain Optical Fourier Transformation

Guan Pengyu, Hirooka Toshihiko, Nakazawa Masataka

Proceedings of the Society Conference of IEICE　2009　(2)　216-216　2009/09/01
Publisher: The Institute of Electronics, Information and Communication Engineers
B-10-40 Polarization and frequency division multiplexed 1 Gsymbol/s, 64 QAM coherent optical transmission with 8.6 bit/s/Hz spectral efficiency over 160 km

Goto Hiroki, Omiya Tatsunori, Kasai Keisuke, Yoshida Masato, Nakazawa Masataka

Proceedings of the Society Conference of IEICE　2009　(2)　220-220　2009/09/01
Publisher: The Institute of Electronics, Information and Communication Engineers
B-10-41 5 Gsymbol/s, 64 QAM-OFDM(30 Gbit/s) coherent optical transmission

Omiya Tatsunori, Kasai Keisuke, Yoshida Masato, Nakazawa Masataka

Proceedings of the Society Conference of IEICE　2009　(2)　221-221　2009/09/01
Publisher: The Institute of Electronics, Information and Communication Engineers
C-4-21 10 GHz-11.5 ps pulse generation form a gain-switched VCSEL at 1.1 μm

Koizumi Kengo, Yoshida Masato, Nakazawa Masataka

Proceedings of the Society Conference of IEICE　2009　(1)　259-259　2009/09/01
Publisher: The Institute of Electronics, Information and Communication Engineers
A 0.4GHz ultranarrow FBG optical filter with 30-dB side lobe suppression

MORI Anne, KASAI Keisuke, YOSHIDA Masato, NAKAZAWA Masataka

IEICE technical report　109　(179)　63-68　2009/08/20
Publisher: The Institute of Electronics, Information and Communication Engineers
ISSN： 0913-5685

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A fiber Bragg grating (FBG) is an attractive optical filter device because of its narrow wavelength selectivity, low loss, compactness, and low cost. Therefore, it is useful for applications such as coherent optical communication systems, optical sensing and optical metrological standard. These applications require both a narrow bandwidth and a high side lobe suppression ratio. We have already demonstrated a 1.3GHz ultranarrow FBG filter with a side lobe suppression ratio of 13dB. In this paper, we report a 0.4GHz FBG filter with a side lobe suppression ratio as high as 30dB by combining a uniform FBG and a λ/4 shifted FBG.
Oscillation characteristics of a 1.5μm FM-eliminated ^<13>C_2H_2 frequency-stabilized laser diode

KASAI Keisuke, NAKAZAWA Masataka

IEICE technical report　109　(174)　73-76　2009/08/13
Publisher: The Institute of Electronics, Information and Communication Engineers
ISSN： 0913-5685

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We demonstrate the frequency stabilization of a 1.5μm laser diode (LD) with a low intensity noise and a narrow linewidth to a ^<13>C_2H_2 linear absorption line. The LD consists of an InP gain chip and an external Bragg reflector made of a PLC waveguide. By employing an external frequency modulator in a frequency stabilization circuit, an FM-eliminated optical output beam was obtained. The frequency stabilities reached as high as 2.3×10^<-11> for τ=1s and 9.1×10^<-12> for τ=100s. Furthermore, a RIN of less than -135dB/Hz, and a linewidth of 4kHz were simultaneously achieved.
Passively mode-locked femtosecond fiber soliton laser with intersubband transition module

SHOHDA Fumio, NAKAZAWA Masataka, AKIMOTO Ryoichi, ISHIKAWA Hiroshi

IEICE technical report　109　(174)　93-96　2009/08/13
Publisher: The Institute of Electronics, Information and Communication Engineers
ISSN： 0913-5685

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An intersubband transition (ISBT) in a quantum well has attracted considerable attention recently since it can be utilized to all-optical switching and signal processing. This is because the ISBT exhibits ultrahigh-speed saturable absorption characteristics faster than 1ps by injecting a TM (Transverse Magnetic) mode optical pulse with high intensity. In this paper, we realize a passively mode-locked fiber laser using the ISBT module as a saturable absorber for the first time. The laser cavity was optimized as a soliton laser, which enabled us to generate a stable soliton pulse. As a result, a 88fs, 42MHz soliton pulse was successfully generated.
Cs optical atomic clock with a mode-hop-free fiber laser

MORISAKI Takahito, YOSHIDA Masato, NAKAZAWA Masataka

IEICE technical report　109　(174)　103-108　2009/08/13
Publisher: The Institute of Electronics, Information and Communication Engineers
ISSN： 0913-5685

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Recently, delivery technique of standards through optical fiber networks has been receiving a lot of attention with respect to their application to frequency standard and measurement. As such optical signal source, we have developed a Cs optical atomic clock that uses a regeneratively mode-locked fiber laser (MLFL) as a microwave oscillator and an optically pumped Cs gas cell as a frequency standard. The Cs optical atomic clock can emit stable transform-limited picosecond pulses with a repetition rate of 9.1926GHz (Cs resonance). However, it was difficult to control the optical frequency of the optical output pulse from the Cs atomic clock because of the MLFL mode-hopping. In this work, we achieved mode-hop-free Cs optical atomic clock by inserting an etalon in the MLFL.
Optical frequency-stabilized and 40GHz repetition-rate-stabilized, regeneratively mode-locked pulse laser

YOSHIDA Masato, KASAI Keisuke, NAKAZAWA Masataka

IEICE technical report　109　(174)　97-102　2009/08/13
Publisher: The Institute of Electronics, Information and Communication Engineers
ISSN： 0913-5685

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Ultrastable mode-locked pulse lasers operating in the GHz region have been receiving a lot of attention with respect to their application to both ultrahigh-speed optical transmission, micro-photonics and optical metrology. In particular, control of the laser frequency is very important for optical coherent communication and optical metrology applications. In this paper, we have succeeded in the simultaneous stabilization of the optical frequency and repetition rate of a 40GHz regeneratively mode-locked picosecond erbium-doped fiber ring laser. The optical frequency was locked to the molecular absorption of C_2H_2 in the 1.5μm band and the repetition rate was stabilized to a 40GHz synthesizer by using a microwave phase-locked loop.
Cs optical atomic clock with a mode-hop-free fiber laser

MORISAKI Takahito, YOSHIDA Masato, NAKAZAWA Masataka

IEICE technical report　109　(173)　103-108　2009/08/13
Publisher: The Institute of Electronics, Information and Communication Engineers
ISSN： 0913-5685

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Recently, delivery technique of standards through optical fiber networks has been receiving a lot of attention with respect to their application to frequency standard and measurement. As such optical signal source, we have developed a Cs optical atomic clock that uses a regeneratively mode-locked fiber laser (MLFL) as a microwave oscillator and an optically pumped Cs gas cell as a frequency standard. The Cs optical atomic clock can emit stable transform-limited picosecond pulses with a repetition rate of 9.1926GHz (Cs resonance). However, it was difficult to control the optical frequency of the optical output pulse from the Cs atomic clock because of the MLFL mode-hopping. In this work, we achieved mode-hop-free Cs optical atomic clock by inserting an etalon in the MLFL.
Optical frequency-stabilized and 40GHz repetition-rate-stabilized, regeneratively mode-locked pulse laser

YOSHIDA Masato, KASAI Keisuke, NAKAZAWA Masataka

IEICE technical report　109　(173)　97-102　2009/08/13
Publisher: The Institute of Electronics, Information and Communication Engineers
ISSN： 0913-5685

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Ultrastable mode-locked pulse lasers operating in the GHz region have been receiving a lot of attention with respect to their application to both ultrahigh-speed optical transmission, micro-photonics and optical metrology. In particular, control of the laser frequency is very important for optical coherent communication and optical metrology applications. In this paper, we have succeeded in the simultaneous stabilization of the optical frequency and repetition rate of a 40GHz regeneratively mode-locked picosecond erbium-doped fiber ring laser. The optical frequency was locked to the molecular absorption of C_2H_2 in the 1.5μm band and the repetition rate was stabilized to a 40GHz synthesizer by using a microwave phase-locked loop.
10GHz-11.5ps pulse generation from a gain-switched VCSEL at 1.1μm

KOIZUMI Kengo, YOSHIDA Masato, NAKAZAWA Masataka

IEICE technical report　109　(173)　89-92　2009/08/13
Publisher: The Institute of Electronics, Information and Communication Engineers
ISSN： 0913-5685

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Vertical cavity surface emitting laser (VCSEL) is an attractive light source because of its low threshold, single longitudinal-mode operation, and high-speed modulation. In addition, the VCSEL is suitable for short pulse generation because of the short photon life time due to the very short cavity. Therefore, a high-speed picosecond pulse source can be realized with a simple configuration by using a gain-switched VCSEL. In this paper, we describe 10GHz pulse generation from gain-switched InGaAs VCSEL at 1.1μm. The shortest pulse pulse width of 11.5ps was obtained after chirp compensation.
10GHz-11.5ps pulse generation from a gain-switched VCSEL at 1.1μm

KOIZUMI Kengo, YOSHIDA Masato, NAKAZAWA Masataka

IEICE technical report　109　(175)　89-92　2009/08/13
Publisher: The Institute of Electronics, Information and Communication Engineers
ISSN： 0913-5685

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Vertical cavity surface emitting laser (VCSEL) is an attractive light source because of its low threshold, single longitudinal-mode operation, and high-speed modulation. In addition, the VCSEL is suitable for short pulse generation because of the short photon life time due to the very short cavity. Therefore, a high-speed picosecond pulse source can be realized with a simple configuration by using a gain-switched VCSEL. In this paper, we describe 10GHz pulse generation from gain-switched InGaAs VCSEL at 1.1μm. The shortest pulse pulse width of 11.5ps was obtained after chirp compensation.
Optical frequency-stabilized and 40GHz repetition-rate-stabilized, regeneratively mode-locked pulse laser

YOSHIDA Masato, KASAI Keisuke, NAKAZAWA Masataka

IEICE technical report　109　(175)　97-102　2009/08/13
Publisher: The Institute of Electronics, Information and Communication Engineers
ISSN： 0913-5685

More details Close

Ultrastable mode-locked pulse lasers operating in the GHz region have been receiving a lot of attention with respect to their application to both ultrahigh-speed optical transmission, micro-photonics and optical metrology. In particular, control of the laser frequency is very important for optical coherent communication and optical metrology applications. In this paper, we have succeeded in the simultaneous stabilization of the optical frequency and repetition rate of a 40GHz regeneratively mode-locked picosecond erbium-doped fiber ring laser. The optical frequency was locked to the molecular absorption of C_2H_2 in the 1.5μm band and the repetition rate was stabilized to a 40GHz synthesizer by using a microwave phase-locked loop.
Cs optical atomic clock with a mode-hop-free fiber laser

MORISAKI Takahito, YOSHIDA Masato, NAKAZAWA Masataka

IEICE technical report　109　(175)　103-108　2009/08/13
Publisher: The Institute of Electronics, Information and Communication Engineers
ISSN： 0913-5685

More details Close

Recently, delivery technique of standards through optical fiber networks has been receiving a lot of attention with respect to their application to frequency standard and measurement. As such optical signal source, we have developed a Cs optical atomic clock that uses a regeneratively mode-locked fiber laser (MLFL) as a microwave oscillator and an optically pumped Cs gas cell as a frequency standard. The Cs optical atomic clock can emit stable transform-limited picosecond pulses with a repetition rate of 9.1926GHz (Cs resonance). However, it was difficult to control the optical frequency of the optical output pulse from the Cs atomic clock because of the MLFL mode-hopping. In this work, we achieved mode-hop-free Cs optical atomic clock by inserting an etalon in the MLFL.
10GHz-11.5ps pulse generation from a gain-switched VCSEL at 1.1μm

KOIZUMI Kengo, YOSHIDA Masato, NAKAZAWA Masataka

IEICE technical report　109　(176)　89-92　2009/08/13
Publisher: The Institute of Electronics, Information and Communication Engineers
ISSN： 0913-5685

More details Close

Vertical cavity surface emitting laser (VCSEL) is an attractive light source because of its low threshold, single longitudinal-mode operation, and high-speed modulation. In addition, the VCSEL is suitable for short pulse generation because of the short photon life time due to the very short cavity. Therefore, a high-speed picosecond pulse source can be realized with a simple configuration by using a gain-switched VCSEL. In this paper, we describe 10GHz pulse generation from gain-switched InGaAs VCSEL at 1.1μm. The shortest pulse pulse width of 11.5ps was obtained after chirp compensation.
Optical frequency-stabilized and 40GHz repetition-rate-stabilized, regeneratively mode-locked pulse laser

YOSHIDA Masato, KASAI Keisuke, NAKAZAWA Masataka

IEICE technical report　109　(176)　97-102　2009/08/13
Publisher: The Institute of Electronics, Information and Communication Engineers
ISSN： 0913-5685

More details Close

Ultrastable mode-locked pulse lasers operating in the GHz region have been receiving a lot of attention with respect to their application to both ultrahigh-speed optical transmission, micro-photonics and optical metrology. In particular, control of the laser frequency is very important for optical coherent communication and optical metrology applications. In this paper, we have succeeded in the simultaneous stabilization of the optical frequency and repetition rate of a 40GHz regeneratively mode-locked picosecond erbium-doped fiber ring laser. The optical frequency was locked to the molecular absorption of C_2H_2 in the 1.5μm band and the repetition rate was stabilized to a 40GHz synthesizer by using a microwave phase-locked loop.
Cs optical atomic clock with a mode-hop-free fiber laser

MORISAKI Takahito, YOSHIDA Masato, NAKAZAWA Masataka

IEICE technical report　109　(176)　103-108　2009/08/13
Publisher: The Institute of Electronics, Information and Communication Engineers
ISSN： 0913-5685

More details Close

Recently, delivery technique of standards through optical fiber networks has been receiving a lot of attention with respect to their application to frequency standard and measurement. As such optical signal source, we have developed a Cs optical atomic clock that uses a regeneratively mode-locked fiber laser (MLFL) as a microwave oscillator and an optically pumped Cs gas cell as a frequency standard. The Cs optical atomic clock can emit stable transform-limited picosecond pulses with a repetition rate of 9.1926GHz (Cs resonance). However, it was difficult to control the optical frequency of the optical output pulse from the Cs atomic clock because of the MLFL mode-hopping. In this work, we achieved mode-hop-free Cs optical atomic clock by inserting an etalon in the MLFL.
光通信インフラの限界に挑戦する

中沢正隆

ITUジャーナル　39　(5)　3-4　2009/05
ペタビット/秒に向けた革新的伝送技術

宮崎哲弥, 福地清, 中沢正隆

ITUジャーナル　39　(5)　19-21　2009/05
Publisher: 日本ITU協会
ISSN： 0916-7544
C-4-5 A film-type saturable absorber with single-wall carbon nanotubes and polyamide and its application to a femtosecond fiber laser

Shohda Fumio, Nakazawa Masataka, Mata Junji, Tsukamoto Jun

Proceedings of the IEICE General Conference　2009　(1)　253-253　2009/03/04
Publisher: The Institute of Electronics, Information and Communication Engineers
B-10-81 160 Gbit/s×8 channel-525 km WDM transmission using time-domain optical Fourier transformation

Guan Pengyu, Okazaki Masatada, Hirano Toshiyuki, Hirooka Toshihiko, Nakazawa Masataka

Proceedings of the IEICE General Conference　2009　(2)　400-400　2009/03/04
Publisher: The Institute of Electronics, Information and Communication Engineers
C-3-3 A 0.4 GHz ultranarrow FBG optical filter with 30-dB side lobe suppression

Mori Anne, Kasai Keisuke, Yoshida Masato, Nakazawa Masataka

Proceedings of the IEICE General Conference　2009　(1)　154-154　2009/03/04
Publisher: The Institute of Electronics, Information and Communication Engineers
B-10-50 1 Gsymbol/s, 6-channel frequency division multiplexed 64 QAM coherent optical transmission

Goto Hiroki, Okamoto Seiji, Omiya Tatsunori, Kasai Keisuke, Yoshida Masato, Nakazawa Masataka

Proceedings of the IEICE General Conference　2009　(2)　369-369　2009/03/04
Publisher: The Institute of Electronics, Information and Communication Engineers
B-10-49 12 Gbit/s, 64 QAM-OFDM coherent optical transmission

Omiya Tatsunori, Goto Hiroki, Kasai Keisuke, Yoshida Masato, Nakazawa Masataka

Proceedings of the IEICE General Conference　2009　(2)　368-368　2009/03/04
Publisher: The Institute of Electronics, Information and Communication Engineers
Ultra-Multilevel Coherent QAM Optical Transmission Technology

NAKAZAWA Masataka

The Review of Laser Engineering　37　(3)　171-176　2009
Publisher: The Laser Society of Japan
DOI： 10.2184/lsj.37.171 　

ISSN： 0387-0200

eISSN： 1349-6603

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optical transmission systems. Coherent quadrature amplitude modulation (QAM) is a very interesting
B-10-77 10 Gbit/s photonic crystal fiber transmission with a l.1μm directly-modulated VCSEL

Koizumi Kengo, Hirooka Toshihiko, Yoshida Masato, Nakazawa Masataka

Proceedings of the IEICE General Conference　396-396　2009
Publisher: The Institute of Electronics, Information and Communication Engineers
次世代光通信基盤技術の展望

中沢正隆, 廣岡俊彦

ケミカルエンジニヤリング　54　(1)　51-57　2009/01
Publisher: 化学工業社
ISSN： 0387-1037
BCI-1-10 Front line of ultra-multi-level modulation technique for coherent QAM transmission

Nakazawa Masataka

Proceedings of the Society Conference of IEICE　2008　(1)　"SS-41"-"SS-42"　2008/09/02
Publisher: The Institute of Electronics, Information and Communication Engineers
B-10-67 Delivery of a Cs optical atomic clock by using JGN II optical networks

Yoshida Masato, Kashiwamura Ikuro, Nakazawa Masataka

Proceedings of the Society Conference of IEICE　2008　(2)　210-210　2008/09/02
Publisher: The Institute of Electronics, Information and Communication Engineers
A 1.3GHz ultranarrow FBG optical filter with 20-dB side lobe suppression

MORI Anne, KASAI Keisuke, YOSHIDA Masato, NAKAZAWA Masataka

IEICE technical report　108　(192)　103-108　2008/08/28
Publisher: The Institute of Electronics, Information and Communication Engineers
ISSN： 0913-5685

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A fiber Bragg grating (FBG) is an attractive optical filter device because of its narrow wavelength selectivity, low loss, compactness, and low cost. Therefore, it is useful for applications such as dense wavelength division multiplexing and coherent optical communication systems. These applications require both a narrow bandwidth and a high side lobe suppression ratio. We have already demonstrated a 1.3GHz ultranarrow FBG filter with a side lobe suppression ratio of 13dB. In this paper, we report a 1.3GHz FBG filter with a side lobe suppression ratio as high as 20dB by combining a uniform FBG and a λ/4 shifted FBG.
A 1.3GHz ultranarrow FBG optical filter with 20-dB side lobe suppression

MORI Anne, KASAI Keisuke, YOSHIDA Masato, NAKAZAWA Masataka

IEICE technical report　108　(193)　103-108　2008/08/28
Publisher: The Institute of Electronics, Information and Communication Engineers
ISSN： 0913-5685

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A fiber Bragg grating (FBG) is an attractive optical filter device because of its narrow wavelength selectivity, low loss, compactness, and low cost. Therefore, it is useful for applications such as dense wavelength division multiplexing and coherent optical communication systems. These applications require both a narrow bandwidth and a high side lobe suppression ratio. We have already demonstrated a 1.3GHz ultranarrow FBG filter with a side lobe suppression ratio of 13dB. In this paper, we report a 1.3GHz FBG filter with a side lobe suppression ratio as high as 20dB by combining a uniform FBG and a λ/4 shifted FBG.
A 1.3GHz ultranarrow FBG optical filter with 20-dB side lobe suppression

MORI Anne, KASAI Keisuke, YOSHIDA Masato, NAKAZAWA Masataka

IEICE technical report　108　(194)　103-108　2008/08/21
Publisher: The Institute of Electronics, Information and Communication Engineers
ISSN： 0913-5685

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A fiber Bragg grating (FBG) is an attractive optical filter device because of its narrow wavelength selectivity, low loss, compactness, and low cost. Therefore, it is useful for applications such as dense wavelength division multiplexing and coherent optical communication systems. These applications require both a narrow bandwidth and a high side lobe suppression ratio. We have already demonstrated a 1.3GHz ultranarrow FBG filter with a side lobe suppression ratio of 13dB. In this paper, we report a 1.3GHz FBG filter with a side lobe suppression ratio as high as 20dB by combining a uniform FBG and a λ/4 shifted FBG.
A 1.3GHz ultranarrow FBG optical filter with 20-dB side lobe suppression

MORI Anne, KASAI Keisuke, YOSHIDA Masato, NAKAZAWA Masataka

IEICE technical report　108　(191)　103-108　2008/08/21
Publisher: The Institute of Electronics, Information and Communication Engineers
ISSN： 0913-5685

More details Close

A fiber Bragg grating (FBG) is an attractive optical filter device because of its narrow wavelength selectivity, low loss, compactness, and low cost. Therefore, it is useful for applications such as dense wavelength division multiplexing and coherent optical communication systems. These applications require both a narrow bandwidth and a high side lobe suppression ratio. We have already demonstrated a 1.3GHz ultranarrow FBG filter with a side lobe suppression ratio of 13dB. In this paper, we report a 1.3GHz FBG filter with a side lobe suppression ratio as high as 20dB by combining a uniform FBG and a λ/4 shifted FBG.
Ultrahigh-speed and coherent optical transmission technologies

M. Nakazawa

New Breeze　20　(2)　16-19　2008/04
B-10-73 All-optical 40 GHz time-domain Fourier transformation using XPM with an optical parabolic pulse

Hirooka Toshihiko, Nakazawa Masataka

Proceedings of the IEICE General Conference　2008　(2)　356　2008/03/05
Publisher: The Institute of Electronics, Information and Communication Engineers
BS-7-11 PMD tolerance of optical QAM

Nakazawa Masataka

Proceedings of the IEICE General Conference　2008　(2)　"S-102"-"S-103"　2008/03/05
Publisher: The Institute of Electronics, Information and Communication Engineers
BS-7-11 PMD tolerance of optical QAM

Nakazawa Masataka

Proceedings of the IEICE General Conference　2008　(2)　"S-102"-"S-103"　2008/03/05
Publisher: The Institute of Electronics, Information and Communication Engineers
B-10-73 All-optical 40 GHz time-domain Fourier transformation using XPM with an optical parabolic pulse

Hirooka Toshihiko, Nakazawa Masataka

Proceedings of the IEICE General Conference　2008　(2)　356-356　2008/03/05
Publisher: The Institute of Electronics, Information and Communication Engineers
C-4-1 Polymer saturable absorber using poly carbonate with single-wall carbon nanotubes and its application to a femtosecond fiber soliton laser in 1.5μm band

Shirato Takafumi, Shoda Fumio, Nakazawa Masataka, Komatsu Kyoji, Kaino Toshikuni

Proceedings of the IEICE General Conference　2008　(1)　284-284　2008/03/05
Publisher: The Institute of Electronics, Information and Communication Engineers
B-10-97 Polarization multiplexed 1 Gsymbol/s, 128 QAM coherent optical transmission

Goto Hiroki, Kasai Keisuke, Yoshida Masato, Nakazawa Masataka

Proceedings of the IEICE General Conference　2008　(2)　380-380　2008/03/05
Publisher: The Institute of Electronics, Information and Communication Engineers
Octave-spanning comb generation and optical frequency measurement using mode-locked fiber lasers

Inaba Hajime, Nakajima Yoshiaki, Minoshima Kaoru, Hong Feng-Lei, Onae Atsushi, Nakazawa Masataka, Matsumoto Hirokazu

The Review of Laser Engineering　36　(0)　26-27　2008
Publisher: The Laser Society of Japan
モード同期ファイバーレーザーと超高速光通信 (特集最近の光周波数制御技術とその応用)

中沢正隆, 廣岡俊彦

光技術コンタクト　45　(11)　579-586　2007/11
Publisher: 日本オプトメカトロニクス協会
ISSN： 0913-7289
CS-7-2 Optical transmission system with multi-level modulation/demodulation formats

Nakazawa Masataka

Proceedings of the Society Conference of IEICE　2007　(1)　"S-80"-"S-81"　2007/08/29
Publisher: The Institute of Electronics, Information and Communication Engineers
B-10-48 160 Gbit/s-1000 km Straight-line DPSK Transmission with Time-domain Optical Fourier Transmission

Okazaki Masatada, Hirooka Toshihiko, Nakazawa Masataka

Proceedings of the Society Conference of IEICE　2007　(2)　242-242　2007/08/29
Publisher: The Institute of Electronics, Information and Communication Engineers
C-4-5 A regeneratively mode-locked fiber laser with a repetition rate stability of 4.9×10^<-15> using a hydrogen maser PLL

Yoshida M., Hirayama T., Nakazawa M., Hagimoto K., Ikegami T.

Proceedings of the Society Conference of IEICE　2007　(1)　211-211　2007/08/29
Publisher: The Institute of Electronics, Information and Communication Engineers
C-4-7 Aλ/4-shifted distributed feedback semiconductor fiber ring laser with a high OSNR and a narrow linewidth

Ho Thi Quynh Anh, Suzuki Akihito, Yoshida Masato, Nakazawa Masataka

Proceedings of the Society Conference of IEICE　2007　(1)　213-213　2007/08/29
Publisher: The Institute of Electronics, Information and Communication Engineers
B-10-54 1Gsymbol/s, 64QAM coherent optical transmission with a high spectral efficiency using a Nyquist filter

Kasai Keisuke, Hongo Jumpei, Goto Hiroki, Yoshida Masato, Nakazawa Masataka

Proceedings of the Society Conference of IEICE　2007　(2)　248-248　2007/08/29
Publisher: The Institute of Electronics, Information and Communication Engineers
カーボンナノチューブを可飽和吸収体として用いたソリトンファイバレーザ

白土剛史, 廣岡俊彦, 吉田真人, 中沢正隆, 戒能俊邦, 小松京嗣

電子情報通信学会大会講演論文集　2007　(1)　209-209　2007/08/29
Publisher: The Institute of Electronics, Information and Communication Engineers
ISSN： 1349-1369
カーボンナノチューブの発光・光学特性とその応用 CNTの超短パルスファイバレーザへの応用

中沢正隆, 廣岡俊彦, 吉田真人, 戒能俊邦, 小松京嗣

月刊Material Stage　7　(4)　37-40　2007/07/10
Publisher: 技術情報協会
ISSN： 1346-3926
Photonic crystal fiber transmission with an 850nm VCSEL

HIROOKA Toshihiko, HASEGAWA Hideaki, OIKAWA Yosuke, NAKAZAWA Masataka, SUZUKI Kenya, INOUE Yasuyuki

IEICE technical report　107　(34)　1-6　2007/05/04
Publisher: The Institute of Electronics, Information and Communication Engineers
ISSN： 0913-5685

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Recently, a photonic crystal fiber (PCF), which has a core region surrounded by multiple air holes, has received a lot of attention because of its new characteristics such as endlessly single-mode operation and arbitrary dispersion control. By combining PCF with inexpensive and high-speed optical devices such as VCSEL and Si-APD, we can construct low-cost and high-speed communication systems in the 800nm region such as 10-40 Gbit/s Ethernet. In this paper, we describe key technologies for 800nm high-speed transmission such as low-dispersion PCF and single-mode VCSEL. Then we describe the demonstration of a single-channel 10Gbit/s and 4×2.5Gbit/s WDM transmission with a directly modulated VCSEL. We also report a single-channel 40Gbit/s and 4×10Gbit/s WDM transmission through the PCF by employing an externally modulated VCSEL. These results indicate that simple, inexpensive and high-speed transmission over short distances such as LAN and FTTH appears to be feasible by combining these devices.
B-10-44 40 Gb/s-2 km photonic crystal fiber transmission with an 850 nm single-mode VCSEL

Hasegawa Hideaki, Oikawa Yosuke, Hirooka Toshihiko, Nakazawa Masataka

Proceedings of the IEICE General Conference　2007　(2)　383-383　2007/03/07
Publisher: The Institute of Electronics, Information and Communication Engineers
B-10-43 10 Gbit/s (4 x 2.5 Gbit/s) photonic crystal fiber transmission with direct modulation of 850 nm VCSELs

Oikawa Yosuke, Hasegawa Hideaki, Hirooka Toshihiko, Nakazawa Masataka, Suzuki Kenya, Inoue Yasuyuki

Proceedings of the IEICE General Conference　2007　(2)　382-382　2007/03/07
Publisher: The Institute of Electronics, Information and Communication Engineers
B-10-67 Effect of time-domain optical Fourier transformation on 160 Gbit/s DPSK transmission

Hirooka Toshihiko, Osawa Kou, Okazaki Masatada, Nakazawa Masataka

Proceedings of the IEICE General Conference　2007　(2)　406-406　2007/03/07
Publisher: The Institute of Electronics, Information and Communication Engineers
C-4-23 Improvement of output characteristics of a ring-type polarization-maintaining λ/4 shifted distributed feedback fiber laser by using 0.98 μm pumping

Ho Thi Quynh Anh, Suzuki Akihito, Nakazawa Masataka

Proceedings of the IEICE General Conference　2007　(1)　285-285　2007/03/07
Publisher: The Institute of Electronics, Information and Communication Engineers
C-4-25 Improvement of output characteristics of an optical frequency tunable 40GHz, picosecond mode-locked fiber laser

Yoshida Masato, Kasai Keisuke, Nakazawa Masataka

Proceedings of the IEICE General Conference　2007　(1)　287-287　2007/03/07
Publisher: The Institute of Electronics, Information and Communication Engineers
C-4-29 Frequency stability improvement of mode-locked laser-type optical atomic clock with an optically pumped Cs gas cell

Hirayama Toru, Yoshida Masato, Nakazawa Masataka, Hagimoto Ken, Ikegami Takeshi

Proceedings of the IEICE General Conference　2007　(1)　291-291　2007/03/07
Publisher: The Institute of Electronics, Information and Communication Engineers
B-10-68 Performance of optical phase-locked loop over 500 km for coherent transmission using heterodyne detection

Kasai Keisuke, Hongo Jumpei, Yoshida Masato, Nakazawa Masataka

Proceedings of the IEICE General Conference　2007　(2)　407-407　2007/03/07
Publisher: The Institute of Electronics, Information and Communication Engineers
BS-7-1 Coherent QAM transmission using a frequency-stabilized laser and an optical phase-locked-loop

Yoshida Masato, Kasai Keisuke, Hongou Jumpei, Nakazawa Masataka

Proceedings of the IEICE General Conference　2007　(2)　"S-47"-"S-48"　2007/03/07
Publisher: The Institute of Electronics, Information and Communication Engineers
Can Humankind Handle the Phase of Optical Beam Like a Microwave?

NAKAZAWA Masataka

36　(2)　59-59　2007/02/10

ISSN： 0389-6625
Optical Fiber Transmission of Standard Signals Using Optical Combs

NAKAZAWA Masataka, HIROOKA Toshihiko, YOSHIDA Masato

The Review of Laser Engineering　35　(10)　649-653　2007
Publisher: The Laser Society of Japan
DOI： 10.2184/lsj.35.649 　

ISSN： 0387-0200

eISSN： 1349-6603

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Recently, the delivery of frequency standards using optical combs through optical fiber networks has become an important subject. When we transmit optical combs through an optical fiber network, it is very important to investigate the distortion in the power spectrum of the longitudinal modes that occurs during the transmission. In this paper, we describe the spectrum deformation of the longitudinal mode that occurs during long-haul transmission through a dispersion-shifted fiber, when we use a 10 GHz mode-locked fiber laser with a linewidth as narrow as 1 kHz as the signal source. We found that the deformation of the longitudinal mode power spectrum occurs mainly at the tail of the spectrum, and the linewidth broadening increases in proportion to the transmission distance. The main reason for the linewidth broadening was the phase fluctuation of the optical fiber caused by temperature fluctuation.
C-4-17 Proposal and its operation of mode-locked laser-type optical atomic clock with an optically pumped Cs gas-cell

Hirayama Toru, Yoshida Masato, Nakazawa Masataka

Proceedings of the Society Conference of IEICE　2006　(1)　231　2006/09/07
Publisher: The Institute of Electronics, Information and Communication Engineers
B-10-24 A 10 Gb/s-2km photonic crystal fiber transmission with a 850nm directly modulated single-mode VCSEL

Hasegawa Hideaki, Oikawa Yosuke, Nakazawa Masataka

Proceedings of the Society Conference of IEICE　2006　(2)　218-218　2006/09/07
Publisher: The Institute of Electronics, Information and Communication Engineers
B-10-23 40 Gbit/s (4×10 Gbit/s) over 5km photonic crystal fiber transmission using VCSELs and AWG at 850nm

Oikawa Yosuke, Hasegawa Hideaki, Suzuki Kenya, Inoue Yasuyuki, Hirooka Toshihiko, Nakazawa Masataka

Proceedings of the Society Conference of IEICE　2006　(2)　217-217　2006/09/07
Publisher: The Institute of Electronics, Information and Communication Engineers
C-4-13 40GHz bright and dark parabolic optical pulse generation using a picosecond optical pulse source and a 64 channel AWG

Hirooka Toshihiko, Osawa Kou, Nakazawa Masataka, Okamoto Katsunari

Proceedings of the Society Conference of IEICE　2006　(1)　227-227　2006/09/07
Publisher: The Institute of Electronics, Information and Communication Engineers
C-4-6 Fabrication of a 1.3GHz ultranarrow band FBG optical filter

Suzuki Akihito, Ho Thi Quynh Anh, Nakazawa Masataka

Proceedings of the Society Conference of IEICE　2006　(1)　220-220　2006/09/07
Publisher: The Institute of Electronics, Information and Communication Engineers
C-4-7 Performance improvement of an acetylene(C_2H_2) frequency-stabilized fiber laser using a highly-doped EDFA

Kasai Keisuke, Suzuki Akihito, Nakazawa Masataka

Proceedings of the Society Conference of IEICE　2006　(1)　221-221　2006/09/07
Publisher: The Institute of Electronics, Information and Communication Engineers
B-10-64 Performance comparison of SMZ and EA type 40GHz optical DEMUX devices in 160Gbit/s OTDM transmission

Osawa Kou, Kumakura Takashi, Hirooka Toshihiko, Nakazawa Masataka

Proceedings of the Society Conference of IEICE　2006　(2)　258-258　2006/09/07
Publisher: The Institute of Electronics, Information and Communication Engineers
B-10-54 64 and 128 coherent QAM preliminary transmission experiments using a frequency-stabilized laser and a local oscillator

Nakazawa Masataka, Hongou Jumpei, Kasai Keisuke, Yoshida Masato

Proceedings of the Society Conference of IEICE　2006　(2)　248-248　2006/09/07
Publisher: The Institute of Electronics, Information and Communication Engineers
C-4-16 An optical frequency tunable 40GHz, picosecond mode-locked fiber laser

Yoshida Masato, Kasai Keisuke, Nakazawa Masataka

Proceedings of the Society Conference of IEICE　2006　(1)　230-230　2006/09/07
Publisher: The Institute of Electronics, Information and Communication Engineers
C-4-17 Proposal and its operation of mode-locked laser-type optical atomic clock with an optically pumped Cs gas-cell

Hirayama Toru, Yoshida Masato, Nakazawa Masataka

Proceedings of the Society Conference of IEICE　2006　(1)　231-231　2006/09/07
Publisher: The Institute of Electronics, Information and Communication Engineers
Fabrication of an ultranarrow band fiber Bragg grating filter with a 1.3GHz bandwidth

SUZUKI Akihito, TAKAHASHI Youhei, NAKAZAWA Masataka

IEICE technical report　106　(211)　11-16　2006/08/17
Publisher: The Institute of Electronics, Information and Communication Engineers
ISSN： 0913-5685

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Various applications of fiber Bragg gratings have been proposed, such as fiber-type narrow band filters or gain-flattening filters for EDFA. We have successfully fabricated an ultranarrow band FBG filter with a linewidth of 1.3GHz by using a 15cm-long polarization-maintaining fiber. In this paper, we describe the details of the fabrication of the FBG and its characteristics. The maximum reflectance and side lobe suppression of the FBG were 65% and 13dB, respectively.
Comparison of optical demultiplexing using SMZ and EA modulator in 160Gbit/s-500km OTDM transmission

HIROOKA Toshihiko, KUMAKURA Takashi, OSAWA Kou, NAKAZAWA Masataka

IEICE technical report　106　(211)　33-38　2006/08/17
Publisher: The Institute of Electronics, Information and Communication Engineers
ISSN： 0913-5685

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Optical time division multiplexing (OTDM) enables ultrahigh-speed transmission at a single wavelength with a bit rate beyond the limit of electrical signal processing. One of the key technologies for OTDM is an optical demultiplexer, which selects a low bit-rate signal from a high-speed OTDM data sequence at a receiver. In this paper, we compare two types of demultiplexers, one with a symmetric Mach-Zehnder (SMZ) switch and the other with an electro-absorption modulator (EAM), when used for 160Gbit/s (4×40Gbit/s) OTDM transmission over 500km. By combining the SMZ switch with a time-domain optical Fourier transmformation technique, we succeeded in obtaining slightly better bit-error rate (BER) performance than with the EAM.
40Gbit/s (4x10Gbit/s)-3km WDM transmission using 850nm VCSEL, AWG, and PCF

OIKAWA Yosuke, HASEGAWA Hideaki, HIROOKA Toshihiko, YOSHIDA Masato, NAKAZAWA Masataka, SUZUKI Kenya, INOUE Yasuyuki

IEICE technical report　106　(211)　27-32　2006/08/17
Publisher: The Institute of Electronics, Information and Communication Engineers
ISSN： 0913-5685

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Recently, a photonic crystal fiber (PCF), which has a core region surrounded by multiple air holes, has received a lot of attention because of its new characteristics such as endlessly single-mode operation and arbitrary dispersion control. By combining a VCSEL, a Si-APD, and a PCF we can construct inexpensive and high-speed communication systems such as 10-40Gbit/s Ethernet. In this paper, we report the first 10Gbit/s x 4 channel WDM transmission over 3km at 850nm using a single-mode PCF without power penalty. We used a special arrayed waveguide grating (AWG) operating at 850nm as a multiplexer and a demultiplexer.
Performance improvement of an acetylene (C_2H_2) frequency-stabilized fiber laser

KASAI Keisuke, SUZUKI Akihito, YOSHIDA Masato, NAKAZAWA Masataka

IEICE technical report　106　(211)　57-62　2006/08/17
Publisher: The Institute of Electronics, Information and Communication Engineers
ISSN： 0913-5685

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An erbium-doped fiber with high Er-ion concentration generally causes output power fluctuation and self-pulsing operation in an erbium fiber laser due to relaxation oscillation. In this report, we employed a new EDF with high Er- and Al-ion concentrations in order to suppress relaxation oscillation and increase output power of the laser. As a result, the output power was more than doubled and the power fluctuation halved. Furthermore the frequency stability of the ^<13>C_2H_2 frequency-stabilized erbium fiber laser reached as high as 1.3×10^<-11> for τ=1s and 2.0×10^<-11> for τ=10^2s. The short term stability of τ=1s was also improved.
Linewidth broadening in high-speed optical comb transmission using a picosecond mode-locked laser

OSAWA Kou, HIROOKA Toshihiko, YOSHIDA Masato, NAKAZAWA Masataka

IEICE technical report　106　(211)　63-68　2006/08/17
Publisher: The Institute of Electronics, Information and Communication Engineers
ISSN： 0913-5685

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An optical pulse train generated from a mode-locked laser has neatly repetitive longitudinal modes in the frequency domain. Since the interval between adjacent modes is defined by the repetition frequency of the laser and each mode has a narrow linewidth with a high SN ratio, the modes can be used for highly accurate optical frequency measurement. Recently, the delivery of such optical frequency standards through optical fiber networks has become an important subject. When we transmit longitudinal modes through an optical fiber network, it is very important to investigate the deformation in the power spectrum of the modes that occurs during the transmission. In this paper, we report the spectrum deformation of the longitudinal mode that occurs during long-haul transmission through dispersion-shifted fiber. We used a 10GHz mode-locked fiber laser with a linewidth as narrow as 1kHz as the signal source. As a result, we found that the deformation of the longitudinal mode power spectrum occurs mainly at the tail of the spectrum and the linewidth broadening increases in proportion to the transmission distance. The main reason for the linewidth broadening in the present experiment was the phase fluctuation of the optical fiber caused by temperature fluctuation or vibration.
CBS-2-3 Ultrahigh-speed distortion-free optical transmission using time-domain optical Fourier transformation

Nakazawa Masataka, Hirooka Toshihiko

Proceedings of the IEICE General Conference　2006　(2)　"S-5"-"S-6"　2006/03/08
Publisher: The Institute of Electronics, Information and Communication Engineers
CBS-2-3 Ultrahigh-speed distortion-free optical transmission using time-domain optical Fourier transformation

Nakazawa Masataka, Hirooka Toshihiko

Proceedings of the IEICE General Conference　2006　(1)　"S-27"-"S-28"　2006/03/08
Publisher: The Institute of Electronics, Information and Communication Engineers
B-10-68 160 Gbit/s-524km OTDM Transmission Using Time-domain Optical Fourier Transformation

Hagiuda Ken-ichi, Kumakura Takashi, Osawa Kou, Hirooka Toshihiko, Nakazawa Masataka

Proceedings of the IEICE General Conference　2006　(2)　388-388　2006/03/08
Publisher: The Institute of Electronics, Information and Communication Engineers
B-10-81 10Gb/s-5km transmission at 850nm using a photonic crystal fiber, VCSEL, and Si-APD

Hasegawa Hideaki, Oikawa Yosuke, Hirooka Toshihiko, Yoshida Masato, Nakazawa Masataka

Proceedings of the IEICE General Conference　2006　(2)　401-401　2006/03/08
Publisher: The Institute of Electronics, Information and Communication Engineers
C-4-2 The fabrication and oscillation characteristics of a polarization-maintained distributed feedback fiber laser at 1.55μm

Suzuki Akihito, Takahashi Yohei, Yoshida Masato, Nakazawa Masataka

Proceedings of the IEICE General Conference　2006　(1)　246-246　2006/03/08
Publisher: The Institute of Electronics, Information and Communication Engineers
C-4-3 A ring-cavity λ/4-shift polarization-maintaining DFB fiber laser and the improvement of the oscillation characteristics

Takahashi Yohei, Suzuki Akihito, Yoshida Masato, Nakazawa Masataka

Proceedings of the IEICE General Conference　2006　(1)　247-247　2006/03/08
Publisher: The Institute of Electronics, Information and Communication Engineers
C-4-4 Characteristics of a ^<13>C_2H_2 frequency-stabilized, polarization-maintained fiber laser at 1.54μm : Measurement of frequency stability with beat note signal

Kasai Keisuke, Yoshida Masato, Nakazawa Masataka

Proceedings of the IEICE General Conference　2006　(1)　248-248　2006/03/08
Publisher: The Institute of Electronics, Information and Communication Engineers
C-4-5 A 1.5μm long cavity single-frequency fiber laser using SOA

Ono Atsushi, Yoshida Masato, Nakazawa Masataka

Proceedings of the IEICE General Conference　2006　(1)　249-249　2006/03/08
Publisher: The Institute of Electronics, Information and Communication Engineers
C-14-7 Ultrastable Cs optical atomic clock with digital frequency stabilization using rectangular modulation

Hirayama T., Yoshida M., Nakazawa M., Hagimoto K., Koga Y., Ikegami T.

Proceedings of the IEICE General Conference　2006　(1)　274-274　2006/03/08
Publisher: The Institute of Electronics, Information and Communication Engineers
カーボンナノチューブをPMMA,PS中に含有した波長1.5μm帯可飽和吸収ポリマーの作製とフェムト秒レーザへの応用

中沢正隆, 中原征二, 広岡俊彦, 吉田真人, 戒能俊邦, 小松京嗣

電子情報通信学会大会講演論文集　2006　(1)　251-251　2006/03/08
Publisher: The Institute of Electronics, Information and Communication Engineers
ISSN： 1349-1369
Transmission of microwaves and optical standards using a fiber laser

Nakazawa Masataka

The Review of Laser Engineering　34　(Supplement)　177-178　2006
Publisher: The Laser Society of Japan
DOI： 10.2184/lsj.34.177 　

ISSN： 0387-0200

eISSN： 1349-6603
能動モード同期ファイバーレーザーの光通信分野への応用 (特集光ファイバーレーザーの新展開)

中沢正隆

O plus E　27　(11)　1280-1287　2005/11
Publisher: 新技術コミュニケ-ションズ
ISSN： 0911-5943
B-10-72 ABCD matrix formalism for distortion-free transmission using time-domain optical Fourier transformation

Nakazawa Masataka, Hirooka Toshihiko

Proceedings of the Society Conference of IEICE　2005　(2)　290　2005/09/07
Publisher: The Institute of Electronics, Information and Communication Engineers
B-10-73 Derivation of analytical expression for third-order dispersion elimination using time-domain optical Fourier transformation

Hirooka Toshihiko, Nakazawa Masataka

Proceedings of the Society Conference of IEICE　2005　(2)　291　2005/09/07
Publisher: The Institute of Electronics, Information and Communication Engineers
B-10-72 ABCD matrix formalism for distortion-free transmission using time-domain optical Fourier transformation

Nakazawa Masataka, Hirooka Toshihiko

Proceedings of the Society Conference of IEICE　2005　(2)　290-290　2005/09/07
Publisher: The Institute of Electronics, Information and Communication Engineers
B-10-73 Derivation of analytical expression for third-order dispersion elimination using time-domain optical Fourier transformation

Hirooka Toshihiko, Nakazawa Masataka

Proceedings of the Society Conference of IEICE　2005　(2)　291-291　2005/09/07
Publisher: The Institute of Electronics, Information and Communication Engineers
C-3-107 Fabrication of a zero-dispersion, dispersion-flattened photonic crystal fiber in the 800 nm region

Hasegawa Hideaki, Oikawa Yosuke, Hirooka Toshihiko, Yoshida Masato, Nakazawa Masataka

Proceedings of the Society Conference of IEICE　2005　(1)　251-251　2005/09/07
Publisher: The Institute of Electronics, Information and Communication Engineers
C-4-13 A C_2H_2 frequency-stabilized fiber laser with a LiNbO_3 optical frequency modulator and a PLL circuit

Kasai Keisuke, Yoshida Masato, Nakazawa Masataka, Shiota Kazunori, Masuda Shin

Proceedings of the Society Conference of IEICE　2005　(1)　294-294　2005/09/07
Publisher: The Institute of Electronics, Information and Communication Engineers
B-10-68 Proposal of ultrahigh-speed distortion-free transmission using all-optical time-domain Fourier transformation

Hirooka Toshihiko, Nakazawa Masataka

Proceedings of the IEICE General Conference　2005　(2)　358　2005/03/07
Publisher: The Institute of Electronics, Information and Communication Engineers
B-10-69 Theoretical study on elimination of waveform distortion using time-domain optical Fourier transformation

Nakazawa Masataka, Hirooka Toshihiko

Proceedings of the IEICE General Conference　2005　(2)　359　2005/03/07
Publisher: The Institute of Electronics, Information and Communication Engineers
B-10-69 Theoretical study on elimination of waveform distortion using time-domain optical Fourier transformation

Nakazawa Masataka, Hirooka Toshihiko

Proceedings of the IEICE General Conference　2005　(2)　359-359　2005/03/07
Publisher: The Institute of Electronics, Information and Communication Engineers
B-10-68 Proposal of ultrahigh-speed distortion-free transmission using all-optical time-domain Fourier transformation

Hirooka Toshihiko, Nakazawa Masataka

Proceedings of the IEICE General Conference　2005　(2)　358-358　2005/03/07
Publisher: The Institute of Electronics, Information and Communication Engineers
B-10-43 Measurement of longitudinal-mode linewidth broadening in ultra-high speed optical pulse transmission

Haneda Kentaro, Osawa Kou, Waiyapot Suttawassuntorn, Nakazawa Masataka

Proceedings of the IEICE General Conference　2005　(2)　333-333　2005/03/07
Publisher: The Institute of Electronics, Information and Communication Engineers
C-4-26 Measurement and investigation of longitudinal mode-hopping of GHz mode-locked fiber laser

Harada Shinji, Kasai Keisuke, Nakazawa Masataka

Proceedings of the IEICE General Conference　2005　(1)　333-333　2005/03/07
Publisher: The Institute of Electronics, Information and Communication Engineers
C-3-76 Broadband dispersion measurement of a photonic crystal fiber with pico-second streak camera and SC light

Hasegawa Hideaki, Oikawa Yousuke, Yoshida Masato, Hirooka Toshihiko, Nakazawa Masataka

Proceedings of the IEICE General Conference　2005　(1)　246-246　2005/03/07
Publisher: The Institute of Electronics, Information and Communication Engineers
C-4-25 An ultrastable PLL mode-locked fiber laser with hydrogen maser clock

Yoshida M., Hirayama T., Yakabe M., Nakazawa M., Koga Y., Hagimoto K., Ikegami T.

Proceedings of the IEICE General Conference　2005　(1)　332-332　2005/03/07
Publisher: The Institute of Electronics, Information and Communication Engineers
C-4-28 Construction of a ^<13>C_2H_2 (acetylene) frequency-stabilized, single-polarization fiber ring laser

Kasai Keisuke, Yoshida Masato, Nakazawa Masataka, Shiota Kazunori, Masuda Shin

Proceedings of the IEICE General Conference　2005　(1)　335-335　2005/03/07
Publisher: The Institute of Electronics, Information and Communication Engineers
Photonic crystal fibers and their applications

NAKAZAWA Masataka

Oyo Buturi　73　(11)　1409-1417　2004/11/10
Publisher: The Japan Society of Applied Physics
DOI： 10.11470/oubutsu.73.11_1409 　

ISSN： 0369-8009

eISSN： 2188-2290

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We describe the fundamentals of two new types of fiber, photonic crystal fiber (PCF) and photonic bandgap fiber (PBF), and their applications. PCF is fabricated by forming small air holes in the cladding of the fiber rather than doping the fiber core with high-index materials. This fiber has very interesting new features including endlessly single-mode operation, zero GVD (Group Velocity Dispersion) in the visible region, and an easily controllable spot-size due to its strongly guiding characteristics that result from the very high relative refractive index between the core and air-holed cladding. By contrast, PBF has air holes not only in its cladding but also in its core, and this enables us to confine an optical beam by utilizing the principle of two-dimensional Bragg diffraction. The air core structure greatly reduces fiber nonlinearity and suggests the feasibility of high-power and low-dispersion transmission.
Photonic crystal fibers and their applications

NAKAZAWA Masataka

73　(11)　1409-1417　2004/11/10
Publisher: 応用物理学会
ISSN： 0369-8009
Effect of stimulated Brillouin scattering in generation of an ultrahigh-speed femtosecond pulse train using a dispersion-decreasing fiber

HAGIUDA Ken-ichi, HIROOKA Toshihiko, NAKAZAWA Masataka

326　13-18　2004/08/26
Ultrahigh-speed parabolic pulse generation for time-domain optical Fourier transformation

HIROOKA Toshihiko, NAKAZAWA Masataka

326　117-122　2004/08/26
Measurement of frequency stability of a Cs optical atomic clock using an opto-microwave oscillator

YAKABE Masatsugu, NITO Ko, YOSHIDA Masato, NAKAZAWA Masataka, KOGA Yasuki, HAGIMOTO Ken, IKEGAMI Takeshi

326　99-104　2004/08/26
Oscillation characteristics of a 10GHz harmonically and regeneratively mode-locked SOA fiber laser

ONO Atsushi, YOSHIDA Masato, NAKAZAWA Masataka

326　105-110　2004/08/26
Development of a C_2H_2 (acetylene) frequency-stabilized and single-polarization fiber laser

KASAI Keisuke, YOSHIDA Masato, NAKAZAWA Masataka

326　111-116　2004/08/26
Measurement of frequency stability of a Cs optical atomic clock using an opto-microwave oscillator

YAKABE Masatsugu, NITO Ko, YOSHIDA Masato, NAKAZAWA Masataka, KOGA Yasuki, HAGIMOTO Ken, IKEGAMI Takeshi

Technical report of IEICE. OFT　104　(262)　19-24　2004/08/20
Publisher: The Institute of Electronics, Information and Communication Engineers
ISSN： 0913-5685

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We demonstrate an ultrastable cesium (Cs) atomic clock with a 9.1926-GHz regeneratively mode-locked fiber laser. By adopting an optically pumped Cs beam tube that has a 1 m-long interaction cavity with a linewidth of 110 Hz, the frequency stabilities are reached as high as 4.8×10^<-12> for τ=1s and 6.3×10^<-13> for τ=50s.
Oscillation characteristics of a 10GHz harmonically and regeneratively mode-locked SOA fiber laser

ONO Atsushi, YOSHIDA Masato, NAKAZAWA Masataka

Technical report of IEICE. OFT　104　(262)　25-30　2004/08/20
Publisher: The Institute of Electronics, Information and Communication Engineers
ISSN： 0913-5685

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A harmonically and regeneratively mode-locked erbium-doped fiber laser can easily produce picosecond transform-limited pulses in the GHz region, so it is very attractive as a light source for an ultrafast optical communication. This fiber laser has a long cavity length and a high O-value of cavity, thus a narrow linewidth (less than 1kHz) of the longitudinal mode can be obtained. This laser is also utilized as a high pure microwave oscillator by using the longitudinal self-beat signal. In this report, we described a 10GHz mode-locked fiber laser using a semiconductor optical amplifier (SOA) instead of a conventional erbium-doped fiber (EDF) as a gain medium, which has a wide tunable range of the cavity length. We measured the linewidth of the laser as a function of the laser cavity.
Development of a C_2H_2 (acetylene) frequency-stabilized and single-polarization fiber laser

KASAI Keisuke, YOSHIDA Masato, NAKAZAWA Masataka

Technical report of IEICE. OFT　104　(262)　31-36　2004/08/20
Publisher: The Institute of Electronics, Information and Communication Engineers
ISSN： 0913-5685

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A frequency-stabilized fiber ring laser using linear absorption line of acetylene molecules is described. The output beam has no frequency modulation. A Fiber Brrag Grating (FBG) with a 3.7GHz bandwidth enabled single-frequency operation by selecting only one longitudinal-mode. The laser frequency was continuously tuned over 2GHz with a longitudinal-mode tracking technique using FBG and was locked to C_2H_2 molecules. The frequency stability (Allan variance) estimated from error signals reached as high as 1.7×10^<-10> for τ=1s and 1.7×10^<-11> for τ=1×10^2s.
Measurement of frequency stability of a Cs optical atomic clock using an opto-microwave oscillator

YAKABE Masatsugu, NITO Ko, YOSHIDA Masato, NAKAZAWA Masataka, KOGA Yasuki, HAGIMOTO Ken, IKEGAMI Takeshi

Technical report of IEICE. OCS　104　(260)　19-24　2004/08/20
Publisher: The Institute of Electronics, Information and Communication Engineers
ISSN： 0913-5685

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We demonstrate an ultrastable cesium (Cs) atomic clock with a 9.1926-GHz regeneratively mode-locked fiber laser. By adopting an optically pumped Cs beam tube that has a 1 m-long interaction cavity with a linewidth of 110 Hz, the frequency stabilities are reached as high as 4.8×10^<-12> for τ=1s and 6.3×10^<-13> for τ=50s.
Oscillation characteristics of a 10GHz harmonically and regeneratively mode-locked SOA fiber laser

ONO Atsushi, YOSHIDA Masato, NAKAZAWA Masataka

Technical report of IEICE. OCS　104　(260)　25-30　2004/08/20
Publisher: The Institute of Electronics, Information and Communication Engineers
ISSN： 0913-5685

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A harmonically and regeneratively mode-locked erbium-doped fiber laser can easily produce picosecond transform-limited pulses in the GHz region, so it is very attractive as a light source for an ultrafast optical communication. This fiber laser has a long cavity length and a high O-value of cavity, thus a narrow linewidth (less than 1kHz) of the longitudinal mode can be obtained. This laser is also utilized as a high pure microwave oscillator by using the longitudinal self-beat signal. In this report, we described a 10GHz mode-locked fiber laser using a semiconductor optical amplifier (SOA) instead of a conventional erbium-doped fiber (EDF) as a gain medium, which has a wide tunable range of the cavity length. We measured the linewidth of the laser as a function of the laser cavity.
Development of a C_2H_2 (acetylene) frequency-stabilized and single-polarization fiber laser

KASAI Keisuke, YOSHIDA Masato, NAKAZAWA Masataka

Technical report of IEICE. OCS　104　(260)　31-36　2004/08/20
Publisher: The Institute of Electronics, Information and Communication Engineers
ISSN： 0913-5685

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A frequency-stabilized fiber ring laser using linear absorption line of acetylene molecules is described. The output beam has no frequency modulation. A Fiber Brrag Grating (FBG) with a 3.7GHz bandwidth enabled single-frequency operation by selecting only one longitudinal-mode. The laser frequency was continuously tuned over 2GHz with a longitudinal-mode tracking technique using FBG and was locked to C_2H_2 molecules. The frequency stability (Allan variance) estimated from error signals reached as high as 1.7×10^<-10> for τ=1s and 1.7×10^<-11> for τ=1×10^2s.
SC-13-6 Regeneratively Mode-locked Fiber Laser in the GHz Region as an Optical Microwave Oscillator

Nakazawa Masataka

Proceedings of the IEICE General Conference　2004　(1)　"S-92"-"S-93"　2004/03/08
Publisher: The Institute of Electronics, Information and Communication Engineers
SC-13-6 Regeneratively Mode-locked Fiber Laser in the GHz Region as an Optical Microwave Oscillator

Nakazawa Masataka

Proceedings of the IEICE General Conference　2004　(1)　"S-92"-"S-93"　2004/03/08
Publisher: The Institute of Electronics, Information and Communication Engineers
B-10-118 Distortion-free transmission of ultrashort optical pulses using optical Fourier transformation

Hirooka Toshihiko, Nakazawa Masataka, Futami Fumio, Watanabe Shigeki

Proceedings of the IEICE General Conference　2004　(2)　489-489　2004/03/08
Publisher: The Institute of Electronics, Information and Communication Engineers
C-3-138 A method for optimizing dispersion characteristics of photonic crystal fibers

Hasegawa Hideaki, Hirooka Toshihiko, Nakazawa Masataka

Proceedings of the IEICE General Conference　2004　(1)　312-312　2004/03/08
Publisher: The Institute of Electronics, Information and Communication Engineers
C-3-134 Recent Progress in Holey Fibers

Nakazawa Masataka

Proceedings of the IEICE General Conference　2004　(1)　308-308　2004/03/08
Publisher: The Institute of Electronics, Information and Communication Engineers
C-3-26 Optical filter characteristics of an ultra-narrow band polarization-maintaining fiber Bragg grating and its application to laser frequency tuning

Yoshida Masato, Kasai Keisuke, Nakazawa Masataka

Proceedings of the IEICE General Conference　2004　(1)　199-199　2004/03/08
Publisher: The Institute of Electronics, Information and Communication Engineers
C-3-144 Splicing characteristics between a photonic crystal fiber and a conventional fiber

Kikegawa Manabu, Hasegawa Hideaki, Yoshida Masato, Hirooka Toshihiko, Nakazawa Masataka

Proceedings of the IEICE General Conference　2004　(1)　318-318　2004/03/08
Publisher: The Institute of Electronics, Information and Communication Engineers
C-4-1 Stimulated Brillouin Scattering in DDF soliton compression of an ultrahigh-speed optical pulse train

Ono Shimpei, Hirooka Toshihiko, Yoshida Masato, Nakazawa Masataka

Proceedings of the IEICE General Conference　2004　(1)　329-329　2004/03/08
Publisher: The Institute of Electronics, Information and Communication Engineers
C-4-19 Oscillation characteristics of a 40 GHz regeneratively mode-locked erbium-doped fiber laser

Harada Shinji, Yoshida Masato, Nakazawa Masataka

Proceedings of the IEICE General Conference　2004　(1)　347-347　2004/03/08
Publisher: The Institute of Electronics, Information and Communication Engineers
Measurements of longitudinal mode linewidth and relative intensity noise in ultrahigh-speed mode-locked semiconductor lasers

HANEDA Kentaro, YOSHIDA Masato, YOKOYAMA Hiroyuki, OGAWA Yo, NAKAZAWA Masataka

Technical report of IEICE. OPE　103　(523)　49-52　2003/12/11
Publisher: The Institute of Electronics, Information and Communication Engineers
ISSN： 0913-5685

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Recently, mode-locked laser diodes (MLLD's) have been intensively studied as light sources for ultrahigh-speed optical communication systems. To improve the timing-jitter and the frequency and amplitude stability of a high repetition rate pulse source, it is important to investigate the longitudinal mode linewidth and relative intensity noise. However, there has been no report on such measurements to date. In this paper we measure the longitudinal mode linewidth and relative intensity noise of 10 GHz and 40 GHz MLLDs and describe new results on these characteristics.
Measurements of longitudinal mode linewidth and relative intensity noise in ultrahigh-speed mode-locked semiconductor lasers

HANEDA Kentaro, YOSHIDA Masato, YOKOYAMA Hiroyuki, OGAWA Yo, NAKAZAWA Masataka

Technical report of IEICE. LQE　103　(526)　49-52　2003/12/11
Publisher: The Institute of Electronics, Information and Communication Engineers
ISSN： 0913-5685

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Recently, mode-locked laser diodes (MLLD's) have been intensively studied as light sources for ultrahigh-speed optical communication systems. To improve the timing-jitter and the frequency and amplitude stability of a high repetition rate pulse source, it is important to investigate the longitudinal mode linewidth and relative intensity noise. However, there has been no report on such measurements to date. In this paper we measure the longitudinal mode linewidth and relative intensity noise of 10 GHz and 40 GHz MLLDs and describe new results on these characteristics.
Photonic Crystal Fibers and Their Application to Ultrashort Pulse Propagation

NAKAZAWA Masataka

32　(10)　606-612　2003/10/10

ISSN： 0389-6625
Photonic Crystal Fibers and Their Application to Ultrashort Pulse Propagation

NAKAZAWA Masataka

32　(10)　606-612　2003/10/10

ISSN： 0389-6625
解説フォトニック結晶ファイバーと超短光パルス—超短パルス光と光通信

中沢正隆

光学 = Japanese journal of optics : publication of the Optical Society of Japan　32　(10)　606-612　2003/10
Publisher: 東京 : 日本光学会
ISSN： 0389-6625
Measurements of Longitudinal Linewidths of 10 GHz, Picosecond Mode-locked Erbium-Doped Fiber Lasers Using a Heterodyne Detection Method

CHOI Samuel, YOSHIDA Masato, NAKAZAWA Masataka

The Transactions of the Institute of Electronics, Information and Communication Engineers C　86　(10)　1054-1062　2003/10/01
Publisher: The Institute of Electronics, Information and Communication Engineers
ISSN： 1345-2827
FDTD Analysis of Fresnel Reflection at a Splice between a Photonic Crystal Fiber and a Conventional Fiber

Hirooka Toshihiko, Hori Yusuke, Hasegawa Hideaki, Yoshida Masato, Nakazawa Masataka

Proceedings of the Society Conference of IEICE　2003　(1)　214-214　2003/09/10
Publisher: The Institute of Electronics, Information and Communication Engineers
C-4-24 モード同期半導体レーザの縦モード線幅およびその強度雑音の測定

羽根田健太郎, 吉田真人, 横山弘之, 小川洋, 中沢正隆

電子情報通信学会ソサイエティ大会講演論文集　2003　(1)　300-300　2003/09/10
Publisher: 一般社団法人電子情報通信学会
光ソリトンと超高速光伝送 (特集光エレクトロニクスの現状と将来)

中沢正隆

学術月報　56　(9)　887-893　2003/09
Publisher: 日本学術振興会
ISSN： 0387-2440
Observation of Huge Fresnel Reflection at a Splicing Point between a Photonic Crystal Fiber and a Conventional Fiber and Its Suppression

YOSHIDA Masato, KIKEGAWA Manabu, NISHIMURA Naoya, NAKAZAWA Masataka

The Transactions of the Institute of Electronics, Information and Communication Engineers C　86　(9)　1007-1016　2003/09/01
Publisher: The Institute of Electronics, Information and Communication Engineers
ISSN： 1345-2827
Observation of an optimum air-hole tapering for splicing between a conventional fiber and a photonic crystal fiber and the reduction of Fresnel reflection

KIKEGAWA Manabu, HASEGAWA Hideaki, YOSHIDA Masato, HIROOKA Toshihiko, NAKAZAWA Masataka

Technical report of IEICE. OCS　103　(255)　51-56　2003/08/21
Publisher: The Institute of Electronics, Information and Communication Engineers
ISSN： 0913-5685

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We have already reported about an observation of a huge Fresnel reflection at a splicing point between a photonic crystal fiber (PCF) and a conventional fiber. This was caused by the difference of the refractive index in the claddings, which leads to a serious problem when utilizing PCF in optical communications. In this paper, the splicing characteristics between a PCF and a conventional fiber were measured in detail, and a splicing condition for suppressing the Fresnel reflection to below the Rayleigh scattering level was clarified. We also measured the cross-sectional structures of PCF near the splicing point by SEM, and a relation between reduction of the Fresnel reflection and air-hole form in the cladding of PCF was discussed.
Observation of Ramsey fringe of a Cs resonance with an ultra-stable pure microwave generated by a regeneratively mode-locked fiber laser

YAKABE Masatsugu, NITO Ko, YOSHIDA Masato, NAKAZAWA Masataka

Technical report of IEICE. OCS　103　(255)　89-94　2003/08/21
Publisher: The Institute of Electronics, Information and Communication Engineers
ISSN： 0913-5685

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A regeneratively mode-locked fiber laser can self-oscillate stably without a synthesizer. The laser has jitter less than 100 fs, so that a beat signal obtained between the longitudinal laser modes can be used as an ultra-stable pure microwave signal. By using this laser as an optical microwave oscillator, a new type of Cs optical atomic clock can be composed and have already been confirmed the operation. In this paper, we observed an atomic resonance of Cs (Ramsey fringe) at 9.1926 GHz for the first time with the optical microwave oscillator, and measured the fundamental characteristics of the Cs optical atomic resonance.
Gaussian and Sech Approximation of a Mode Field in Photonic Crystal Fibers

HIROOKA Toshihiko, HORI Yusuke, NAKAZAWA Masataka

Technical report of IEICE. OFT　103　(257)　57-62　2003/08/14
Publisher: The Institute of Electronics, Information and Communication Engineers
ISSN： 0913-5685

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Mode field distribution in the cladding region of photonic crystal fibers (PCF) depends strongly on the wavelength or the cladding structure. In this report, we formulate the least square approximation of the electrical field distribution of the fundamental mode (HEn mode) in PCF by a Gaussian and a hyperbolic-secant (sech) function. The analysis shows that the shape of the mode field varies with the ratio of a hole diameter d and a pitch A. The mode field is found to be approximated by a Gaussian function for large d/Λ values (i.e., for strongly guiding structure) as in step-index fibers, and by a sech function for small d/Λ values (for weakly guiding structure).
Observation of an optimum air-hole tapering for splicing between a conventional fiber and a photonic crystal fiber and the reduction of Fresnel reflection

KIKEGAWA Manabu, HASEGAWA Hideaki, YOSHIDA Masato, HIROOKA Toshihiko, NAKAZAWA Masataka

Technical report of IEICE. OFT　103　(257)　51-56　2003/08/14
Publisher: The Institute of Electronics, Information and Communication Engineers
ISSN： 0913-5685

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We have already reported about an observation of a huge Fresnel reflection at a splicing point between a photonic crystal fiber (PCF) and a conventional fiber. This was caused by the difference of the refractive index in the claddings, which leads to a serious problem when utilizing PCF in optical communications. In this paper, the splicing characteristics between a PCF and a conventional fiber were measured in detail, and a splicing condition for suppressing the Fresnel reflection to below the Rayleigh scattering level was clarified. We also measured the cross-sectional structures of PCF near the splicing point by SEM, and a relation between reduction of the Fresnel reflection and air-hole form in the cladding of PCF was discussed.
Observation of Ramsey fringe of a Cs resonance with an ultra-stable pure microwave generated by a regeneratively mode-locked fiber laser

YAKABE Masatsugu, NITO Ko, YOSHIDA Masato, NAKAZAWA Masataka

Technical report of IEICE. OFT　103　(257)　89-94　2003/08/14
Publisher: The Institute of Electronics, Information and Communication Engineers
ISSN： 0913-5685

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A regeneratively mode-locked fiber laser can self-oscillate stably without a synthesizer. The laser has jitter less than 100 fs, so that a beat signal obtained between the longitudinal laser modes can be used as an ultra-stable pure microwave signal. By using this laser as an optical microwave oscillator, a new type of Cs optical atomic clock can be composed and have already been confirmed the operation. In this paper, we observed an atomic resonance of Cs (Ramsey fringe) at 9.1926 GHz for the first time with the optical microwave oscillator, and measured the fundamental characteristics of the Cs optical atomic resonance.
Trends in Femtosecond Technology Supporting Next Generation Industrial Bases

NAKAZAWA Masataka

The Journal of the Institute of Electronics, Information, and Communication Engineers　86　(8)　586-587　2003/08/01
Publisher: The Institute of Electronics, Information and Communication Engineers
ISSN： 0913-5693
Ultrafast OTDM Transmission Technology

NAKAZAWA Masataka

The Journal of the Institute of Electronics, Information and Communication Engineers　86　(8)　588-593　2003/08/01
Publisher: The Institute of Electronics, Information and Communication Engineers
ISSN： 0913-5693
High Precicion Frequency Standards Using Mode-Locked Fiber Lasers

NAKAZAWA Masataka

The Review of laser engineering　31　(7)　443-449　2003/07/15
Publisher: レ-ザ-学会
ISSN： 0387-0200
Observation of huge Fresnel reflections at splicing points between a photonic crystal fiber and a conventional fiber and their suppression method

Yoshida Masato, Kikegawa Manabu, Nakazawa Masataka

Proceedings of the IEICE General Conference　2003　(1)　229-229　2003/03/03
Publisher: The Institute of Electronics, Information and Communication Engineers
Optical Amplifiers and Their Application to Fiber Lasers

NAKAZAWA Masataka

Japanese journal of optics　32　(2)　119-128　2003/02/10
Publisher: 応用物理学会分科会日本光学会
ISSN： 0389-6625
フォトニック結晶ファイバー (特集フォトニック結晶)

中沢正隆

O plus E　25　(2)　181-190　2003/02
Publisher: 新技術コミュニケ-ションズ
ISSN： 0911-5943
High Precision Frequency Standards Using Mode-Locked Fiber Lasers

NAKAZAWA Masataka

The Review of Laser Engineering　31　(7)　443-449　2003
Publisher: The Laser Society of Japan
DOI： 10.2184/lsj.31.443 　

ISSN： 0387-0200

eISSN： 1349-6603

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We describe an application of ultrashort fiber lasers to high precision frequency standards that enable us to measure unknown optical frequencies directly. Mode-locked lasers have a unique feature in that there are neatly repetitive longitudinal modes in the output pulses, which form an optical comb. Therefore, if we can stabilize the comb separation, which is a longitudinal mode separation, we can use such a comb as an extremely precise “optical measure”. In this paper, we describe two kinds of frequency standard application of mode-locked fiber lasers. One is passive mode locking which has a fine and long comb. However, it is difficult to extract one of the optical combs. The other is active mode locking which has a coarse and short comb. Nevertheless, it is advantageous in that it makes it possible to extract one of the standard combs with an optical filter and transmit it through an optical network. Finally, a cesium (Cs) optical atomic clock is described as an application to a new frequency standard.
Observation of huge Fresnel reflection at a splicing point between a photonic crystal fiber and a conventional fiber and its suppression

YOSHIDA Masato, NISHIMURA Naoya, NAKAZAWA Masataka

Technical report of IEICE. PS　102　(267)　1-6　2002/08/15
Publisher: The Institute of Electronics, Information and Communication Engineers
ISSN： 0913-5685

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It is possible to realize index-guiding optical fibers by forming small air holes in the fiber cladding instead of doping its core with high-index materials. These fibers are called index-guiding type photonic crystal fibers. The fibers have very interesting new features including endlessly single-mode operation, zero GVD in the visible region, and easy control of the spot-size because of the strongly guiding characteristics that result from the very high relative refractive index between the core and cladding with air holes. In this study, we describe splicing characteristics between photonic crystal fibers and conventional fibers. A large Fresnel reflection is observed at the splicing point, which causes serious problems when utilizing photonic crystal fibers in conventional optical communications. A reduction method of the Fresnel reflection is also presented.
Observation of huge Fresnel reflection at a splicing point between a photonic crystal fiber and a conventional fiber and its suppression

YOSHIDA Masato, NISHIMURA Naoya, NAKAZAWA Masataka

Technical report of IEICE. OFT　102　(269)　1-6　2002/08/15
Publisher: The Institute of Electronics, Information and Communication Engineers
ISSN： 0913-5685

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It is possible to realize index-guiding optical fibers by forming small air holes in the fiber cladding instead of doping its core with high-index materials. These fibers are called index-guiding type photonic crystal fibers. The fibers have very interesting new features including endlessly single-mode operation, zero GVD in the visible region, and easy control of the spot-size because of the strongly guiding characteristics that result from the very high relative refractive index between the core and cladding with air holes. In this study, we describe splicing characteristics between photonic crystal fibers and conventional fibers. A large Fresnel reflection is observed at the splicing point, which causes serious problems when utilizing photonic crystal fibers in conventional optical communications. A reduction method of the Fresnel reflection is also presented.
Observation of huge Fresnel reflection at a splicing point between a photonic crystal fiber and a conventional fiber and its suppression

YOSHIDA Masato, NISHIMURA Naoya, NAKAZAWA Masataka

Technical report of IEICE. OCS　102　(265)　1-6　2002/08/15
Publisher: The Institute of Electronics, Information and Communication Engineers
ISSN： 0913-5685

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It is possible to realize index-guiding optical fibers by forming small air holes in the fiber cladding instead of doping its core with high-index materials. These fibers are called index-guiding type photonic crystal fibers. The fibers have very interesting new features including endlessly single-mode operation, zero GVD in the visible region, and easy control of the spot-size because of the strongly guiding characteristics that result from the very high relative refractive index between the core and cladding with air holes. In this study, we describe splicing characteristics between photonic crystal fibers and conventional fibers. A large Fresnel reflection is observed at the splicing point, which causes serious problems when utilizing photonic crystal fibers in conventional optical communications. A reduction method of the Fresnel reflection is also presented.
レーザー解説フォトニック結晶ファイバ—「超高速ファイバ非線形光学」解説小特集号

中沢正隆

レーザー研究 = The review of laser engineering : レーザー学会誌 / レーザー学会編　30　(8)　426-434　2002/08
Publisher: 吹田 : レーザー学会
ISSN： 0387-0200
招待講演フォトニック結晶ファイバによる500～1300nm波長帯での超高速光通信の可能性について

中沢正隆

電子情報通信学会技術研究報告 = IEICE technical report : 信学技報　101　(704)　1-11　2002/03/08
Publisher: 東京 : 電子情報通信学会
ISSN： 0913-5685
Possibility of 500-1300nm Ultrahigh-speed Optical Communication Using Photonic Crystal Fibers

NAKAZAWA Masataka

Technical report of IEICE. OFT　101　(704)　1-12　2002/03/01
Publisher: The Institute of Electronics, Information and Communication Engineers
ISSN： 0913-5685

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It is possible to realize index-guiding optical fibers by forming small air holes in the fiber cladding instead of doping its core with high-index materials. These fibers are called index-guiding type photonic crystal fibers. The fibers have very interesting new features including endlessly single-mode operation, zero GVD in the visible region, and easy control of the spot-size because of the strongly guiding characteristics that result from the very high relative refractive index between the core and cladding with air holes. We discuss the possibility of high-speed optical communication over 500 〜1300 nm.
Possibility of 500~1300 nm Ultrahigh-speed Optical Communication Using Photonic Crystal Fibers.

中沢正隆

電子情報通信学会技術研究報告　101　(704(OFT2001 105-114))　2002

ISSN： 0913-5685
Photonic Crystal Fibers.

NAKAZAWA Masataka

The Review of Laser Engineering　30　(8)　426-434　2002
Publisher: The Laser Society of Japan
DOI： 10.2184/lsj.30.426 　 10.2320/matertrans.mt-y2023004_references_DOI_QOFivqHGBk70Xow54dCr64FLaSH 　 10.2497/jjspm.68.409_references_DOI_QOFivqHGBk70Xow54dCr64FLaSH 　

ISSN： 0387-0200

eISSN： 1349-6603

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We describe the fundamentals of two new types of fiber, photonic crystal fiber (PCF) and photonic bandgap fiber (PBF). PCF is fabricated by forming small air holes in the cladding of the fiber rather than doping the fiber core with high-index materials. This fiber has very interesting new features including endlessly single-mode operation, zero GVD in the visible region, and an easily controllable spot-size due to the strongly guiding characteristics that result from the very high relative refractive index between the core and air-holed cladding. By contrast, PBF has air holes not only in its cladding but also in its core, and this enables us to confine an optical beam by using the principle of two-dimensional Bragg diffraction. The air core structure greatly reduces fiber nonlinearity and suggests the feasibility of high power transmission.
ANULTRASHORT PULSE SOURCE FOR HIGH-SPEED OPTICAL COMMUNICATION AND ITS COMPRESSION TECHNIQUE

Nakazawa Masataka

Proceedings of the Society Conference of IEICE　2001　(1)　267-268　2001/08/29
Publisher: The Institute of Electronics, Information and Communication Engineers
ANULTRASHORT PULSE SOURCE FOR HIGH-SPEED OPTICAL COMMUNICATION AND ITS COMPRESSION TECHNIQUE

Nakazawa Masataka

Proceedings of the Society Conference of IEICE　2001　(1)　267-268　2001/08/29
Publisher: The Institute of Electronics, Information and Communication Engineers
A frequency-shifted feedback fiber laser and its application to optical measurements

YOSHIDA M., NAKAZAWA M., ITO H.

IEICE technical report. Component parts and materials　101　(258)　53-58　2001/08/17
Publisher: The Institute of Electronics, Information and Communication Engineers
ISSN： 0913-5685

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In frequency-shifted feedback lasers (FSF lasers), a frequency shift is imposed on an intracavity light field by feedback of the first-order diffracted light of an acousto-optic modulator. In this report, we describe the performance of the FSF laser with an erbium-doped fiber as a gain medium and its application to measurements for group velocity dispersion and polarization mode dispersion of optical fibers. We also describe a new FSF laser which incorporates an active mode-locking technique. Because of the mode-locking mechanism, the phase between the modes are completely locked, and this indicates that one can greatly improve the signal to noise ratio of the beat signal (> 20 dB)in optical homodyne measurements.
A frequency-shifted feedback fiber laser and its application to optical measurements

YOSHIDA M., NAKAZAWA M., ITO H.

IEICE technical report. EMD　101　(256)　53-58　2001/08/17
Publisher: The Institute of Electronics, Information and Communication Engineers
ISSN： 0913-5685

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In frequency-shifted feedback lasers (FSF lasers), a frequency shift is imposed on an intracavity light field by feedback of the first-order diffracted light of an acousto-optic modulator. In this report, we describe the performance of the FSF laser with an erbium-doped fiber as a gain medium and its application to measurements for group velocity dispersion and polarization mode dispersion of optical fibers. We also describe a new FSF laser which incorporates an active mode-locking technique. Because of the mode-locking mechanism, the phase between the modes are completely locked, and this indicates that one can greatly improve the signal to noise ratio of the beat signal(>20 dB)in optical homodyne measurements.
A frequency-shifted feedback fiber laser and its application to optical measurements

YOSHIDA M., NAKAZAWA M., ITO H.

Technical report of IEICE. OPE　101　(260)　53-58　2001/08/17
Publisher: The Institute of Electronics, Information and Communication Engineers
ISSN： 0913-5685

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In frequency-shifted feedback lasers (FSF lasers), a frequency shift is imposed on an intracavity light field by feedback of the first-order diffracted light of an acousto-optic modulator. In this report, we describe the performance of the FSF laser with an erbium-doped fiber as a gain medium and its application to measurements for group velocity dispersion and polarization mode dispersion of optical fibers. We also describe a new FSF laser which incorporates an active mode-locking technique. Because of the mode-locking mechanism, the phase between the modes are completely locked, and this indicates that one can greatly improve the signal to noise ratio of the beat signal(>20 dB)in optical homodyne measurements.
A frequency-shifted feedback fiber laser and its application to optical measurements

YOSHIDA M., NAKAZAWA M., ITO H.

Technical report of IEICE. LQE　101　(262)　53-58　2001/08/17
Publisher: The Institute of Electronics, Information and Communication Engineers
ISSN： 0913-5685

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In frequency-shifted feedback lasers(FSF lasers), a frequency shift is imposed on an intracavity light field by feedback of the first-order diffracted light of an acousto-optic modulator. In this report, we describe the performance of the FSF laser with an erbium-doped fiber as a gain medium and its application to measurements for group velocity dispersion and polarization mode dispersion of optical fibers. We also describe a new FSF laser which incorporates an active mode-locking technique. Because of the mode-locking mechanism, the phase between the modes are completely locked, and this indicates that one can greatly improve the signal to noise ratio of the beat signal(>20 dB)in optical homodyne measurements.
Origin of Group Delay Ripple in Chirped Fiber Bragg Gratings and Its Effective Reduction Method

KOMUKAI Tetsuro, INUI Tetsuro, NAKAZAWA Masataka

The Transactions of the Institute of Electronics,Information and Communication Engineers. C　84　(8)　673-680　2001/08/01
Publisher: The Institute of Electronics, Information and Communication Engineers
ISSN： 1345-2827
Proposal of an Optical Adaptive Equalizer Using a Nonlinearly Chirped Fiber Bragg Grating Pair

INUI T., KOMUKAI T., NAKAZAWA M.

Technical report of IEICE. OFT　101　(63)　7-12　2001/05/11
Publisher: The Institute of Electronics, Information and Communication Engineers
ISSN： 0913-5685

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We describe an optical adaptive equalizer using a pair of nonlinearly chirped fiber Bragg gratings mounted on multilayer piezoelectric transducers (MLP). This equalizer can equalize second- and third- order dispersion of 80 km long dispersion-shifted fibers. The gratings were fabricated with phase masks that were multiply-overwritten with an electron beam. This technique reduced the group delay ripple to ± 1.90 ps. The operation region can be tuned up to 5.6 nm by applying 50 V to the MLP. These results indicate that this device is applicable to adaptive equalization.
Tunable mode-locked lasers for subcarrier address processing and routing

TAMURA K. R., KOMUKAI T., SATO K., INOUE Y., SUGITA A., NAKAZAWA M.

Technical report of IEICE. OCS　101　(56)　39-44　2001/05/11
Publisher: The Institute of Electronics, Information and Communication Engineers

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Recently, the use of subcarriers have been proposed for addressing nodes in optical networks. An attractive aspect of subcarriers is that they can be processed using analog techniques, which opens the possibility for using all-optical techniques in the future. In this paper, we propose the use of tunable mode-locked lasers for processing subcarrier addresses and demonstrate a simple way that they can be applied to routing. Such techniques may find use in future optical networks based on optical burst switching.
Fundamental characteristics of a variable dispersion equalizer using nonlinearly chirped fiber Bragg gratings with a small group delay ripple

INUI Tetsuro, KOMUKAI Tetsuro, NAKAZAWA Masataka

Proceedings of the IEICE General Conference　2001　(2)　575-575　2001/03/07
Publisher: The Institute of Electronics, Information and Communication Engineers
A Highly-sensitive Waveform Measurement of a 160Gbit/s Signal with an Optical Sampling using a Quasi-Phasematched Mixing in LiNbO_3 Waveguide

Kawanishi S., Yamamoto T., Fejer M., Nakazawa M.

Proceedings of the IEICE General Conference　2001　(2)　532-532　2001/03/07
Publisher: The Institute of Electronics, Information and Communication Engineers
A 40 Gbit/s-500 km SMF transmission experiment using fiber gratings with a small group delay ripple

SAHARA Akio, KOMUKAI Tetsuro, YAMADA Eiich, NAKAZAWA Masataka

Proceedings of the IEICE General Conference　2001　(2)　591-591　2001/03/07
Publisher: The Institute of Electronics, Information and Communication Engineers
Single-wavelength 1.28Tbit/s-70km OTDM transmission using femto second pulses

Nakazawa Masataka, Yamamoto Takashi, Tamura Kohichi

Proceedings of the IEICE General Conference　2001　(2)　527-527　2001/03/07
Publisher: The Institute of Electronics, Information and Communication Engineers
54-fs Soliton Pulse Generation Using a Polarization Maintaining Dispersion-Flattened Dispersion Decreasing Fiber

TAMURA K. R., KUBOTA H., NAKAZAWA M.

Technical report of IEICE. OFT　100　(460)　7-12　2000/11/15
Publisher: The Institute of Electronics, Information and Communication Engineers
ISSN： 0913-5685

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We report on the design rules for dispersion decreasing fiber pulse compressors and report on the realization of a polarization-maintaining dispersion-flattened dispersion decreasing fiber. Dispersion-flattening is shown to be necessary for obtaining sub-100 fs pulse widths and for reducing the dependence of the compression on input wavelength. The polarization is stabilized by the PANDA construction, however, the compression properties differ depending on the polarization axis due to a dispersion in the dispersion tapers. The slow axis is optimal for use due to the lack of polarization instability at high powers, so the compression was optimized for this state of polarization. At the optimum input power, which minimizes the pulse-to-pulse jitter, the pulse width was 54 fs, spectral width was 54 nm, and the time-bandwidth product was 0.36. The pulse width decreased to as short as 43 fs with increased input power, though at the expense of higher jitter.
Causes of mode-hoppings in CW Erbium-doped fiber ring laser

INABA Hajime, AKIMOTO Yoshiaki, KOMUKAI Tetsuro, NAKAZAWA Masataka

Technical report of IEICE. OPE　100　(349)　13-17　2000/10/06
Publisher: The Institute of Electronics, Information and Communication Engineers
ISSN： 0913-5685

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Erbium-doped fiber ring laser(EDFRL)has advantages of narrow-linewidth, low-noise, sufficient power, long-lifetime and alignment-free. However, it also has disadvantages of mode-competition and mode-hopping under mode-competition is suppressed. We suppressed the mode-competition instabilities by using an optical fiber Bragg grating(FBG)and operated the EDFRL without mode-hopping by using a Fabry-Perot filter. The causes and the countermeasures are considered from the experimental results. It is noted that the optimization of the parameters of a Fabry-Perot filter, a short resonator and the temperature control of FBG are important.
An examination of the causes of group delay ripple in chirped fiber Bragg gratings

KOMUKAI Tetsuro, INUI Tetsuro, NAKAZAWA Masataka

Technical report of IEICE. OFT　100　(315)　31-35　2000/09/15
Publisher: The Institute of Electronics, Information and Communication Engineers
ISSN： 0913-5685

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In this report, we investigated the origin of group delay ripple in a chirped fiber Bragg grating. Comparing the devices realized with a chirped phase mask method and a mechanical chirping method, we found that the group delay ripples are mainly caused by the phase errors of chirped phase masks.
Highly stable femtosecond soliton pulse compression using a polarization-maintaining dispersion-flattened dispersion decreasing fiber

Tamura K. R., Nakazawa M.

Proceedings of the Society Conference of IEICE　2000　(1)　279-279　2000/09/07
Publisher: The Institute of Electronics, Information and Communication Engineers
Numerical Analyses of Ultrafast Fiber Laser with Soliton Effect

Kubota Hirokazu, Nakazawa Masataka

Proceedings of the Society Conference of IEICE　2000　(1)　278-278　2000/09/07
Publisher: The Institute of Electronics, Information and Communication Engineers
Optical frequency domain reflectometry domain with a frequency-shifted feedback mode locked erbium doped fiber laser

Yoshida M., Fujimoto M., Nakamura K., Nakazawa M., Ito H.

Proceedings of the Society Conference of IEICE　2000　(2)　432-432　2000/09/07
Publisher: The Institute of Electronics, Information and Communication Engineers
Numerical Analyses of Ultrashort Fiber Laser with Optical Nonlinear Effect

KUBOTA Hirokazu, NAKAZAWA Masataka

Technical report of IEICE. OCS　100　(230)　61-66　2000/07/21
Publisher: The Institute of Electronics, Information and Communication Engineers
ISSN： 0913-5685

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We performed numerical analyses of the transient waveform change and steady state waveforms ultrashort fiber laser incorporating self phase modulation effect. The relation ship of pulse width and fiber length, and the characteristics of dispersion-managed fiber laser are described.
640Gbit/s (40Gbit/s x 16 channel) dispersion-managed DWDM soliton transmission over 1,000km with spectral efficiency of 0.4bit/s/Hz

SUZUKI Kazunori, KUBOTA Hirokazu, NAKAZAWA Masataka

IEICE technical report. Communication systems　100　(129)　19-24　2000/06/16
Publisher: The Institute of Electronics, Information and Communication Engineers
ISSN： 0913-5685

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A 640 Gbit/s(40 Gbit/s x 16 channel)dense WDM soliton transmission experiment over 1000km are reported. The dispersion-managed transmission line comprised conventional 1.3 μm single mode fibers and dispersion compensating fibers with dispersion slope compensation and a repeater span of 50 km. The spectral efficiency was as high as 0.4 bit/s/Hz.
100 KM Transmission of a 640 Gbit/s OTDM Signal using Femtosecond Pulses

YAMAMOTO Takashi, YOSHIDA Eiji, TAMURA Kohichi R., NAKAZAWA Masataka

The Transactions of the Institute of Electronics,Information and Communication Engineers B　83　(5)　625-633　2000/05/25
Publisher: The Institute of Electronics, Information and Communication Engineers
ISSN： 1344-4697
A Variable Dispersion Equalizer Using a Nonlinearly Chirped Fiber Bragg Grating Pair Mounted on Multi-Layer Piezoelectric Transducers

INUI T., KOMUKAI T., NAKAZAWA M.

Technical report of IEICE. OFT　100　(85)　19-23　2000/05/19
Publisher: The Institute of Electronics, Information and Communication Engineers
ISSN： 0913-5685

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We describe a variable dispersion equalizer using a pair of nonlinearly chirped fiber Bragg gratings mounted on multi-layer piezoelectric transducers. This equalizer has a tunable dispersion range of ±15 ps/nm and enables us to equalize second- and third-order dispersion of dispersion-shifted fibers with different zero dispersion wavelengths over 6 nm. These results indicate that this equalizer is applicable to adaptive equalization as well as preset equalization.
Optical fiber technology in current ultrahigh-speed optical TDM transmission

NAKAZAWA Masataka

Technical report of IEICE. OFT　100　(84)　7-15　2000/05/18
Publisher: The Institute of Electronics, Information and Communication Engineers
ISSN： 0913-5685

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In this report, we describe recent advances in optical fiber technology which allowed us to achieve 640 Gbit/s OTDM transmission over 100 km. The fibers we used were dispersion-shifted fibers, dispersion-flattened fibers, dispersion-decreasing fibers, dispersion compensation fibers and reverse dispersion fibers. These were used for optical pulse compression and pulse energy stabilization using soliton effects, the construction of a wideband dispersion-flattened transmission line for femtosecond pulses, suppression of FWM with dispersion management, and optical switching using a NOLM. Finally, we emphasize how precisice control of dispersion along the direction of propagation is critical for achieving ultrahigh-speed optical transmission.
Reduction of delay ripple on chirped fiber Bragg gratings made with electron beam overwritten phase masks

KOMUKAI Tetsuro, INUI Tetsuro, NAKAZAWA Masataka

Proceedings of the IEICE General Conference　2000　(1)　241-241　2000/03/07
Publisher: The Institute of Electronics, Information and Communication Engineers
Measurement of short pulse transmission characteristic of microring resonator Add/Drop filter

Suzuki S., Kokubun Y., Nakazawa M., Yamamoto T., Chu S.T.

Proceedings of the IEICE General Conference　2000　(1)　443-443　2000/03/07
Publisher: The Institute of Electronics, Information and Communication Engineers
A new optical routing technique using a time-to-wavelength mapped mode-locked laser(TWML)

Tamura K.R., Komukai T., Nakazawa M.

Proceedings of the IEICE General Conference　2000　(1)　378-378　2000/03/07
Publisher: The Institute of Electronics, Information and Communication Engineers
Measurement of ultra-short pulse transmission characteristic of microring resonator Add/Drop filter

SUZUKI Shuichi, KOKUBUN Yasuo, NAKAZAWA Masataka, YAMAMOTO Takashi, CHU Sai Tak

Technical report of IEICE. OPE　99　(651)　85-90　2000/02/23
Publisher: The Institute of Electronics, Information and Communication Engineers
ISSN： 0913-5685

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The ultra-short pulse transmission characteristic of verticallly coupled microring resonator filter was measured and the transmission capacity per channel was evaluated. The pulse width of output from a filter was measured to be 3.4 psec, when an input pulse with 1.2 psec width and a sech^2 pulse shape from a fiber laser was incident on a microring resonator filter with FWHM of 0.75m, (94GHz). From this result, the maximum transmission capacity of this filter was evaluated to be about 50Gbit/sec. The pulse broadening through the filter was theoretically analyzed, and it was seen that the values of pulse broadening evaluated from the bandwidth of filter spectrum response is in good agreement with the measured results.
Compensation of polarization mode dispersion using in-line synchronous modulation in soliton transmission system

SAHARA Akio, KUBORA Hirokazu, NAKAZAWA Masataka

Technical report of IEICE. OFT　99　(538)　25-30　2000/01/14
Publisher: The Institute of Electronics, Information and Communication Engineers
ISSN： 0913-5685

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We numerically evaluated the transmission quality using Q-factor in the 40 and 80 Gbit / s soliton transmission system, and we analyzed the effect of polarization mode dispersion on the transmission quality. It is difficult to transmit the optical soliton over long distance in the presence of large PMD. However in-line synchronous modulation technique can improve transmission quality in the presence of large PMD.
A Time-to-Wavelength Mapped Mode-locked Laser and Its Application to Wavelength Routing

TAMURA K. R., KOMUKAI T., NAKAZAWA M.

Technical report of IEICE. OFT　99　(538)　31-35　2000/01/14
Publisher: The Institute of Electronics, Information and Communication Engineers
ISSN： 0913-5685

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Time-to-wavelength mapped lasers(TWML)are mode-locked sources which incorporate an element in the cavity that maps a unique transit delay to a given input wavelength. One way that such an element may be realized is to use a concatenation of fiber Bragg gratings. These lasers are tuned by varying the mode-locking frequency. Since the wavelength is fixed by intracavity filtering elements, it has the potential for high wavelength reproducibility and may fulfill the requirements needed for fast tunable lasers in wavelength-routed networks. We show how these lasers can be used to make a simple wavelength router where a subcarrier frequency serves as a routing address.
Ultra high speed and high capacity optical communication

Nakazawa Masataka

The Review of Laser Engineering　28　(Supplement)　163-164　2000
Publisher: The Laser Society of Japan
DOI： 10.2184/lsj.28.supplement_163 　

ISSN： 0387-0200

eISSN： 1349-6603
640Gbit/s-100km TDM signal transmission using femtosecond pulses

YAMAMOTO Takashi, YOSHIDA Eiji, TAMURA Kohichi, NAKAZAWA Masataka

Proceedings of the Society Conference of IEICE　1999　(2)　233-233　1999/08/16
Publisher: The Institute of Electronics, Information and Communication Engineers
Compensation of polarization mode dispersion in optical soliton transmission using in-line synchronous modulation

SAHARA Akio, KUBOTA Hirokazu, NAKAZAWA Masataka

Proceedings of the Society Conference of IEICE　1999　(2)　256-256　1999/08/16
Publisher: The Institute of Electronics, Information and Communication Engineers
160Gbit/s TDM soliton transmission over 10,000km using in-line synchronous modulation

Nakazawa M., Suzuki K., Kubota H.

Proceedings of the Society Conference of IEICE　1999　(2)　261-261　1999/08/16
Publisher: The Institute of Electronics, Information and Communication Engineers
Pedestal removal from femtosecond pulses using a DI-NOlM

Tamura K. R., Nakazawa M.

Proceedings of the Society Conference of IEICE　1999　(1)　230-230　1999/08/16
Publisher: The Institute of Electronics, Information and Communication Engineers
Effect of zero-GVD wavelength on SC pulse generation using fibers with normal GVD

Kubota Hirokazu, Tamura Kohichi, Nakazawa Masataka

Proceedings of the Society Conference of IEICE　1999　(1)　229-229　1999/08/16
Publisher: The Institute of Electronics, Information and Communication Engineers
Prototype of 10 GHz, 1ps PLL mode-locked fiber laser

Yoshida Eiji, Nakazawa Masataka

Proceedings of the Society Conference of IEICE　1999　(1)　237-237　1999/08/16
Publisher: The Institute of Electronics, Information and Communication Engineers
Controlling ASE noise for coherent WDM light source generated by soliton compression

KUBOTA Hirokazu, TAMURA Kohichi R., NAKAZAWA Masataka

Technical report of IEICE. OCS　99　(242)　53-56　1999/07/30
Publisher: The Institute of Electronics, Information and Communication Engineers
ISSN： 0913-5685

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The coherence of a high order soliton pulse train and the corresponding super-continuum are greatly degraded due to the random evolution of the high order soliton in the presence of noise. This random evolution may be interpreted as the amplification of random ASE by the modulation instability gain of the high order soliton. We show that this random evolution can be suppressed by filtering an appropriate portion of the ASE spectrum.
High repetition rate mode-locked fiber laser

YOSHIDA Eiji, NAKAZAWA Masataka

Technical report of IEICE. OCS　99　(242)　41-45　1999/07/30
Publisher: The Institute of Electronics, Information and Communication Engineers
ISSN： 0913-5685

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A stable optical short pulse source with a high repetition rate is very important to realize future ultra-high speed optical communication systems. We report on the regenerative mode-locking of a fiber laser and show that this laser can emit a stable 1 ps pulse train at 10 GHz. In addition, we report a phase-locked-loop technique to lock the repetition-frequency of the laser to an external signal. The jitter characteristics of the output pulse are found to be extremely low.
10Gbit/s-3,000km Dispersion Managed Soliton Transmission Using Chirped Fiber Bragg Gratings

YAMADA Eiichi, KOMUKAI Tetsuro, NAKAZAWA Masataka

Technical report of IEICE. OCS　99　(242)　63-67　1999/07/30
Publisher: The Institute of Electronics, Information and Communication Engineers
ISSN： 0913-5685

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We have succeeded in a 10 Gbit/s dispersion-managed soliton transmission over 3,000 km using 1.3 μm single-mode fibers and chirped fiber Bragg gratings (CFBG) at 1.55 μm. One repeater span was comprised of 52 km-long SMF, and the soliton pulses were dispersion-compensated by a CFBG after being amplified by an erbium-doped fiber amplifier (EDFA). The BER at 2,900 km was less than 1x10^<-9> and long-distance soliton transmission was achieved with this configuration. This CFBG technique is very advantageous for improving the performance of SMF transmission lines and this means we can construct high-speed network systems with installed SMF transmission lines at low cost.
Wavelength-tunable 100-fs soliton generation using a dispersion-flattened DDF

Tamura K., Nakazawa M.

Proceedings of the IEICE General Conference　1999　(1)　362　1999/03/08
Publisher: The Institute of Electronics, Information and Communication Engineers
Timing jitter characteristics of a PLL, regeneratively mode-locked fiber laser at 10 GHz

Yoshida Eiji, Nakazawa Masataka

Proceedings of the IEICE General Conference　1999　(1)　361　1999/03/08
Publisher: The Institute of Electronics, Information and Communication Engineers
Wavelength-tunable 100-fs soliton generation using a dispersion-flattened DDF

Tamura K., Nakazawa M.

Proceedings of the IEICE General Conference　1999　(1)　362-362　1999/03/08
Publisher: The Institute of Electronics, Information and Communication Engineers
Timing jitter characteristics of a PLL, regeneratively mode-locked fiber laser at 10 GHz

Yoshida Eiji, Nakazawa Masataka

Proceedings of the IEICE General Conference　1999　(1)　361-361　1999/03/08
Publisher: The Institute of Electronics, Information and Communication Engineers
The Characteristics of a Single-Frequency Fiber Laser and its Application to Sensing

INABA Hajime, AKIMOTO Yoshiaki, NAKAZAWA Masataka

1999　(1)　19-23　1999/02/10
Ultrashort Pulse Generation at High Repetition Rate from Mode-Locked Fiber Lasers.

YOSHIDA Eiji, NAKAZAWA Masataka

The Review of Laser Engineering　27　(4)　274-280　1999
Publisher: The Laser Society of Japan
DOI： 10.2184/lsj.27.274 　

ISSN： 0387-0200

eISSN： 1349-6603

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A stable optical short pulse source with a high repetition rate is very important for realizing future ultrahigh speed optical communication. Of the many potential techniques, an actively mode-locked fiber laser is one of the most attractive sources for generating high quality picosecond pulses at GHz repetition rates. In this paper, we report a regeneratively mode-locked fiber laser which emits a 1-3 ps transform limited pulse at 10 GHz in the 1.53 to 1.55μm wavelength region. This laser can be locked to an external signal by operating a phase-locked loop technique. By using this pulse source and an adiabatic soliton compression technique, a 170 fs pulse train at 10 GHz was generated. Finally, we show the excellent jitter characteristics of the laser.
Preface for Topical Papers on Ultrahigh Speed and Ultrahigh Capacity Optical Communication Technologies

NAKAZAWA Masataka

The Review of Laser Engineering　27　(4)　230-230　1999
Publisher: The Laser Society of Japan
DOI： 10.2184/lsj.27.230 　

ISSN： 0387-0200

eISSN： 1349-6603
Ultrashort pulse generation using a mode-locked fiber laser

TAMURA K., YOSHIDA E., NAKAZAWA M.

19　145-146　1999/01/01

ISSN： 0913-6355
B-10-105 Higher Order Dispersion Equalization Using Non-linear Chirped Fiber Bragg Grating Pair

Imai T., Inui T., Komukai T., Nakazawa M.

Proceedings of the IEICE General Conference　10　466-466　1999
Publisher: The Institute of Electronics, Information and Communication Engineers
640Gbit/s-60km, 320Gbit/s-120km TDM ultrahigh speed optical communications

YOSHIDA Eiji, NAKAZAWA Masataka, YAMAMOTO Takashi

1998　(69)　19-24　1998/10/29
640Gbit/s-60km, 320Gbit/s-120km TDM ultrahigh speed optical communications

YOSHIDA Eiji, YAMAMOTO Takashi, NAKAZAWA Masataka

Technical report of IEICE. OCS　98　(374)　19-24　1998/10/29
Publisher: The Institute of Electronics, Information and Communication Engineers

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Time-division-multiplexed 640 and 320 Gbit/s signals have been successfully transmitted over 60 and 120 km, respectively. The data signal was generated by multiplexing a 10 Gbit/s femtosecond pulse train with a planar lightwave circuit. The femtosecond pulse train was generated by compressing output pulses from a fiber laser. The width of the data pulse was 400 fs and the second and third-order dispersions in the transmission fiber were fully compensated. A nonlinear optical loop mirror with a walk-off of less than ±100 fs was used to demultiplex the signal to 10 Gbit/s.
Theoretical/Experimental Study of Gordon-Haus Jitter of Ultrashort Solitons Compressed in Dispersion Decreasing Fibers

Tamura K., Nakazawa M.

Proceedings of the Society Conference of IEICE　1998　(1)　327　1998/09/07
Publisher: The Institute of Electronics, Information and Communication Engineers
Long phase-error-free fiber Bragg gratings

KOMUKAI Tetsuro, NAKAZAWA Masataka

Proceedings of the Society Conference of IEICE　1998　(1)　182　1998/09/07
Publisher: The Institute of Electronics, Information and Communication Engineers
640 Gbit/s-60km transmission experiment using a femtosecond optical pulse train

NAKAZAWA Masataka, YOSHIDA Eiji, YAMAMOTO Takashi, YAMADA Eiichi

Proceedings of the Society Conference of IEICE　1998　(2)　388-388　1998/09/07
Publisher: The Institute of Electronics, Information and Communication Engineers
Demultplexing of a subterabit TDM optical signal using an ultrafast NOLM

YAMAMOTO Takashi, YOSHIDA Eiji, YAMADA Eiichi, NAKAZAWA Masataka

Proceedings of the Society Conference of IEICE　1998　(2)　474-474　1998/09/07
Publisher: The Institute of Electronics, Information and Communication Engineers
Theoretical/Experimental Study of Gordon-Haus Jitter of Ultrashort Solitons Compressed in Dispersion Decreasing Fibers

Tamura K., Nakazawa M.

Proceedings of the Society Conference of IEICE　1998　(1)　327-327　1998/09/07
Publisher: The Institute of Electronics, Information and Communication Engineers
Long phase-error-free fiber Bragg gratings

KOMUKAI Tetsuro, NAKAZAWA Masataka

Proceedings of the Society Conference of IEICE　1998　(1)　182-182　1998/09/07
Publisher: The Institute of Electronics, Information and Communication Engineers
10GHzフェムト秒ファイバレーザとその波長多重光源への変換技術(論文賞贈呈)

吉田英二, 田村公一, 山田英一, 中沢正隆

電子情報通信学会誌　81　(6)　555-555　1998/06/25
Publisher: 一般社団法人電子情報通信学会
ISSN： 0913-5693
Demultiplexing of subterabit TDM optical signal by using ultrafast nonlinear optical loop mirror

YAMAMOTO Takashi, YOSHIDA Eiji, YAMADA Eiichi, NAKAZAWA Masataka

Technical report of IEICE. PS　98　(110)　19-24　1998/06/18
Publisher: The Institute of Electronics, Information and Communication Engineers

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A 640 Gbit/s TDM optical signal has been successfully demultiplexed to 10 Gbit/s with a walk-off free, ultrafast 450-m long nonlinear optical loop mirror(NOLM). The NOLM consists of nine 50-m long dispersion flattened fibers(DFF)with different group delay characteristics. The walk-off between the signal and control pulses for each of the nine fibers was within ±400fs. By properly connecting them, a total walk-off of less than ±100fs has been successfully achieved.
Higher order dispersion compensation using nonlinearly chirped fiber Bragg gratings

KOMUKAI Tetsuro, NAKAZAWA Masataka

Proceedings of the IEICE General Conference　1998　(1)　205　1998/03/06
Publisher: The Institute of Electronics, Information and Communication Engineers
Pump intensity dependence of optical pulse compression gain via four-wave mixing

YAMAMOTO Takashi, NAKAZAWA Masataka

Proceedings of the IEICE General Conference　1998　(1)　427　1998/03/06
Publisher: The Institute of Electronics, Information and Communication Engineers
Ultrahigh speed soliton control technologies and their applications

NAKAZAWA Masataka

Proceedings of the IEICE General Conference　1998　(1)　421　1998/03/06
Publisher: The Institute of Electronics, Information and Communication Engineers
Dispersion tuning of a chirped fiber Bragg grating without a center wavelength shift

IMAI Takeshi, KOMUKAI Tetsurou, NAKAZAWA Masataka

Proceedings of the IEICE General Conference　1998　(1)　290-290　1998/03/06
Publisher: The Institute of Electronics, Information and Communication Engineers
Higher order dispersion compensation using nonlinearly chirped fiber Bragg gratings

KOMUKAI Tetsuro, NAKAZAWA Masataka

Proceedings of the IEICE General Conference　1998　(1)　205-205　1998/03/06
Publisher: The Institute of Electronics, Information and Communication Engineers
A Prototype of 20 Gbit/s Optical Soliton Transmission System

Yamada Eiichi, Kaitsuka Toshiyuki, Iijima Hideo, Nakazawa Masataka

Proceedings of the IEICE General Conference　1998　(2)　542-542　1998/03/06
Publisher: The Institute of Electronics, Information and Communication Engineers
Intracavity dispersion effects of a regeneratively and harmonically FM mode-locked erbium-doped fiber laser

Yoshida Eiji, Tamura Kohichi, Nakazawa Masataka

Proceedings of the IEICE General Conference　1998　(1)　433-433　1998/03/06
Publisher: The Institute of Electronics, Information and Communication Engineers
Forced Phase Modulation and Self Phase Modulation Effects in Dispersion-Tuned Mode-locked Fiber Lasers

Tamura K., Yoshida E., Nakazawa M.

Proceedings of the IEICE General Conference　1998　(1)　432-432　1998/03/06
Publisher: The Institute of Electronics, Information and Communication Engineers
Ultrahigh speed soliton control technologies and their applications

NAKAZAWA Masataka

Proceedings of the IEICE General Conference　1998　(1)　421-421　1998/03/06
Publisher: The Institute of Electronics, Information and Communication Engineers
Pump intensity dependence of optical pulse compression gain via four-wave mixing

YAMAMOTO Takashi, NAKAZAWA Masataka

Proceedings of the IEICE General Conference　1998　(1)　427-427　1998/03/06
Publisher: The Institute of Electronics, Information and Communication Engineers
Mode-Locked Fiber Lasers for Ultra-High Speed Optical Communications

YOSHIDA E., TAMURA K., NAKAZAWA M.

248　27-31　1998/02/06
High-speed,Long-distance Communication Using Optical Soliton

Nakazawa Masataka, Kubota Hirokazu

Journal of the Japan Society of Mechanical Engineers　100　(949)　1240-1241　1997/12/05
Publisher: The Japan Society of Mechanical Engineers
ISSN： 0021-4728
Efficient optical pulse compression with optical gain via four-wave mixing

YAMAMOTO Takashi, NAKAZAWA Masataka

Proceedings of the Society Conference of IEICE　1997　(1)　249　1997/08/13
Publisher: The Institute of Electronics, Information and Communication Engineers
Proposal of a Q-Map method for evaluation of transmission characteristic of WDM systems and its application to soliton transmission.

Sahara Akio, Kubota Hirokazu, Nakazawa Masataka

Proceedings of the Society Conference of IEICE　1997　(2)　492-492　1997/08/13
Publisher: The Institute of Electronics, Information and Communication Engineers
Theoretical and experimental comparison between optical soliton, NRZ, and RZ pulse transmission at zero GVD

NAKAZAWA Masataka, KUBOTA Hirokazu, SAHARA Akio, YAMADA Eiichi, YAMAMOTO Takashi

Proceedings of the Society Conference of IEICE　1997　(2)　490-490　1997/08/13
Publisher: The Institute of Electronics, Information and Communication Engineers
Anultra narrow band apodised fiber Bragg grating and its application to spectral filtering

KOMUKAI Tetsuro, Tamura Kohichi, NAKAZAWA Masataka

Proceedings of the Society Conference of IEICE　1997　(1)　150-150　1997/08/13
Publisher: The Institute of Electronics, Information and Communication Engineers
Characterization of a dispersion-tuned fiber laser

Tamura K., Yoshida E., Nakazawa M.

Proceedings of the Society Conference of IEICE　1997　(1)　259-259　1997/08/13
Publisher: The Institute of Electronics, Information and Communication Engineers
PLL operation of a hamonically and regeneratively mode-locked fiber laser using as an optical VCO

Yoshida Eiji, Nakazawa Masataka

Proceedings of the Society Conference of IEICE　1997　(1)　258-258　1997/08/13
Publisher: The Institute of Electronics, Information and Communication Engineers
A 10 GHz, 2 ps harmonically and regeneratively FM mode-locked fiber laser

Yoshida E., Tamura K., Nakazawa M.

Proceedings of the IEICE General Conference　1997　(1)　383-383　1997/03/06
Publisher: The Institute of Electronics, Information and Communication Engineers
60 Gb/s WDM (20 Gb/s×3 channels) soliton transmission over 10,000 km

Suzuki K., Kubota H., Nakazawa M.

Proceedings of the IEICE General Conference　1997　(1)　375-375　1997/03/06
Publisher: The Institute of Electronics, Information and Communication Engineers
High Repetition Rate Dispersion-Tuned Fiber Laser Locked to External Clock

Tamura K., Yoshida E., Nakazawa M.

Proceedings of the IEICE General Conference　1997　(1)　382-382　1997/03/06
Publisher: The Institute of Electronics, Information and Communication Engineers
Fabrication of a high-quality long-fiber Bragg grating by monitoring a 3.1 eV (400 nm) radiation

KOMUKAI Tetsuro, NAKAZAWA Masataka

Proceedings of the IEICE General Conference　1997　(1)　333-333　1997/03/06
Publisher: The Institute of Electronics, Information and Communication Engineers
Femtosecond Fiber Lasers

Nakazawa M.

Proceedings of the IEICE General Conference　1997　(1)　515-516　1997/03/06
Publisher: The Institute of Electronics, Information and Communication Engineers
Efficient optical pulse compression via four-wave mixing

YAMAMOTO Takashi, NAKAZAWA Masataka

Technical report of IEICE. LQE　97　(35)　49-54　1997/02/14
Publisher: The Institute of Electronics, Information and Communication Engineers

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We report a new technique for optical pulse compression, which utilizes the four-wave mixing efficiency's dependence on pump power. A small-core fiber with a mode field diameter of 4.2 μm is used and the pump wavelength is set to 3.1 nm longer than the zero-dispersion wavelength of the fiber. In this case, the efficiency of the four-wave mixing increases rapidly as the pump power increases. Therefore when a signal pulse is coupled into the fiber with a pump pulse, only the peak of the signal is amplified sharply in time. By using this characteristic, a 93 ps signal pulse is compressed to a 20 ps pulse and the peak power is amplified by 29.0 dB. The wavelength-converted signal has a pulse width of 21 ps, and the peak power of the converted signal is larger by as much as 28.9 dB than that of the input signal.
Efficient optical pulse compression via four-wave mixing

YAMAMOTO Takashi, NAKAZAWA Masataka

Technical report of IEICE. LQE　97　(35)　49-54　1997/02/14
Publisher: The Institute of Electronics, Information and Communication Engineers

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We report a new technique for optical pulse compression, which utilizes the four-wave mixing efficiency's dependence on pump power. A small-core fiber with a mode field diameter of 4.2 μm is used and the pump wavelength is set to 3.1 nm longer than the zero-dispersion wavelength of the fiber. In this case, the efficiency of the four-wave mixing increases rapidly as the pump power increases. Therefore when a signal pulse is coupled into the fiber with a pump pulse, only the peak of the signal is amplified sharply in time. By using this characteristic, a 93 ps signal pulse is compressed to a 20 ps pulse and the peak power is amplified by 29.0 dB. The wavelength-converted signal has a pulse width of 21 ps, and the peak power of the converted signal is larger by as much as 28.9 dB than that of the input signal.
High-speed, Long-distance Communication Using Optical Soliton

Journal of the Society of Mechanical Engineers　100　(949)　1240-1241　1997
Publisher: The Japan Society of Mechanical Engineers
DOI： 10.1299/jsmemag.100.949_1240 　

eISSN： 2424-2675
Recent progress in optical soliton communication and its future prospects: Analogy between optical pulse transmission and laser mode-locking

NAKAZAWA Masataka

Oyo Buturi　66　(9)　922-932　1997
Publisher: The Japan Society of Applied Physics
DOI： 10.11470/oubutsu1932.66.922 　

ISSN： 0369-8009

eISSN： 2188-2290
Optical Fiber Bragg Gratings.

KOMUKAI Tetsuro, NAKAZAWA Masataka

The Journal of the Institute of Electronics,Information and Communication Engineers　79　(12)　pp.1245-1247　1996/12/25
Publisher: The Institute of Electronics, Information and Communication Engineers
ISSN： 0913-5693
Efficient four-wave mixing in an optical fiber with intensity dependent phase matching

YAMAMOTO Takashi, NAKAZAWA Masataka

Technical report of IEICE. OME　96　(284)　61-66　1996/10/03
Publisher: The Institute of Electronics, Information and Communication Engineers

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The gain of wavelength conlversion via four-wave mixing in an optical fiber is investigated when using pump intensity-dependent phase matching. A fiber with a small mode-field diameter (4.2μm) and small dissension slope (0.0307 ps/km/nm^2) is used for the four-wave mixing. With the signal wavelength set to longer than the zero-dispersion wavelength of the fiber by 9.2 nm, a wavelength conversion gain of more than 5 dB is obtained over a plump wavelength range of more than 8 nm. When the pump wavelength is set to longer than the zero-dispersion wavelength by 1.2 nm, the conversion gain increases rapidly from -17.5 dB to +1.8 dB when the pump power is raised by only 3.0 dB (from 6.5 dBm to 9.5 dBm).
Efficient four-wave mixing in an optical fiber with intensity dependent phase matching

YAMAMOTO Takashi, NAKAZAWA Masataka

Technical report of IEICE. OME　96　(284)　61-66　1996/10/03
Publisher: The Institute of Electronics, Information and Communication Engineers

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The gain of wavelength conlversion via four-wave mixing in an optical fiber is investigated when using pump intensity-dependent phase matching. A fiber with a small mode-field diameter (4.2μm) and small dissension slope (0.0307 ps/km/nm^2) is used for the four-wave mixing. With the signal wavelength set to longer than the zero-dispersion wavelength of the fiber by 9.2 nm, a wavelength conversion gain of more than 5 dB is obtained over a plump wavelength range of more than 8 nm. When the pump wavelength is set to longer than the zero-dispersion wavelength by 1.2 nm, the conversion gain increases rapidly from -17.5 dB to +1.8 dB when the pump power is raised by only 3.0 dB (from 6.5 dBm to 9.5 dBm).
High capacity optical transmission in 1.3μm SM fiber using dispersion-allocated soliton

KUBOTA Hirokazu, SAHARA Akio, NAKAZAWA Masataka

Proceedings of the Society Conference of IEICE　1996　(1)　292-292　1996/09/18
Publisher: The Institute of Electronics, Information and Communication Engineers
40Gbit/s WDM (10Gbit/s×4 channels) soliton transmission over 10,000 km

Suzuki K, Yamada E, Kimura Y, Nakazawa M

Proceedings of the Society Conference of IEICE　1996　(1)　286-286　1996/09/18
Publisher: The Institute of Electronics, Information and Communication Engineers
A 750 fs, 10 GHz regeneratively mode-locked fiber laser in the 1.5μm region

Yoshida E, Nakazawa M

Proceedings of the Society Conference of IEICE　1996　(1)　384-385　1996/09/18
Publisher: The Institute of Electronics, Information and Communication Engineers
Generation of 10 GHz 16 Channel WDM Pulse Trains from a Femtosecond Fiber Laser

Tamura K, Yoshida E, Nakazawa M

Proceedings of the Society Conference of IEICE　1996　(1)　386-387　1996/09/18
Publisher: The Institute of Electronics, Information and Communication Engineers
Efficient four-wave mixing in an optical fiber with intensity dependent phase matching

YAMAMOTA Takashi, IMAI Takeshi, NAKAZAWA Masataka

Proceedings of the Society Conference of IEICE　1996　(1)　338-338　1996/09/18
Publisher: The Institute of Electronics, Information and Communication Engineers
Terabit optical signal demultiplexing with a femtosecond nonlinear fiber loop mirror

YAMADA Eiichi, SUZUKI Kazuroni, NAKAZAWA Masataka

Proceedings of the Society Conference of IEICE　1996　(1)　388-389　1996/09/18
Publisher: The Institute of Electronics, Information and Communication Engineers
Femtosecond fiber laser at 10GHz and its application as a multi-wavelength optical source

YOSHIDA Eiji, TAMURA Kohichi, YAMADA Eiichi, NAKAZAWA Masataka

Technical report of IEICE. LQE　96　(38)　43-48　1996/05/16
Publisher: The Institute of Electronics, Information and Communication Engineers

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A stable optical short pulse source in the GHz region is required to realize future ultra-high speed optical communication. We report the generation of a 170-250fs pulse train at a repetition rate of 10GHz in the 1.5μm region through the use of a stable harmonically and regeneratively mode-locked erbium-doped fiber laser and a dispersion-decreasing erbium-doped fiber amplifier. This pulse train was amplified up to an average power of 0.5W by using a high power erbium-ytterbium-doped fiber amplifier. The peak power was as high as 190W. By slicing the broad spectrum of the amplified femtosecond pulse into 8 channels with an optical filter, we succeeded in producing an 80GHz multi-wavelength optical source. This source will play an important roll in wavelength-division-multiplexed transmission.
High power picosecond / femtosecond fiber lasers using chirped fiber gratings / high dispersion fibers

TAMURA Kohichi, KOMUKAI Tetsuro, NAKAZAWA Masataka

Technical report of IEICE. LQE　96　(38)　37-42　1996/05/16
Publisher: The Institute of Electronics, Information and Communication Engineers

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For passively mode-locked fiber lasers to replace larger bulk laser systems, it is necessary for the pulse energies to be comparable to those of bulk systems. We discuss how highly dispersive components such as chirped fiber Bragg gratings or high dispersion fibers can be used to increase the pulse energies of fiber lasers. We also discuss various methods of power extraction from the laser cavity. These techniques allow the construction of picosecond and femtosecond fiber lasers with output pulse energies approaching the nanajoule level.
Generation of a Single Polarization, Single Wavelength Terabit/s Optical Data Pulse Train Using a Femtosecond Laser Source

YAMADA Eiichi, YOSHIDA Eiji, NAKAZAWA Masataka

Technical report of IEICE. LQE　96　(38)　49-54　1996/05/16
Publisher: The Institute of Electronics, Information and Communication Engineers

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This paper reports on the successful generation of a single polarization, single wavelength terabit/s optical data pulse train using a 10Gb/s femtosecond pulse source and an optical time domain multiplexing (OTDM) technique. A stable train of 3ps pulses at a 10GHz repetition rate was generated from a harmonically and regeneratively mode-locked fiber laser, and a femtosecond data signal at 10Gb/s was obtained by adiabatically compressing the picosecond pulse train in a dispersion decreasing erbium-doped fiber. The compressed pulse width was as short as 220fs. The OTDM consisted of a silica based planar lightwave circuit with a seven-step Mach-Zehnder interferometer. High speed data pulse trains at 640Gb/s and 1.28Tb/s were amplified in a high power EDFA, and the output pulse width broadened to 400fs. It is shown that the phase differences between multiplexed pulses have a large influence on the spectral profile.
160 Gbit/s-225 km soliton data transmission

Suzuki K., Yamada E., Yoshida E., Nakazawa M.

Proceedings of the IEICE General Conference　1996　(1)　344-344　1996/03/11
Publisher: The Institute of Electronics, Information and Communication Engineers
0.5 W average power, 10 GHz repetition rate femtosecond source in the 1.55μm region

Tamura K., Yoshida E., Yamada E., Nakazawa M.

Proceedings of the IEICE General Conference　1996　(1)　340-340　1996/03/11
Publisher: The Institute of Electronics, Information and Communication Engineers
The optical cable amplifiers

Kimura Yasuo, Nakazawa Masataka

Proceedings of the IEICE General Conference　1996　(1)　327-327　1996/03/11
Publisher: The Institute of Electronics, Information and Communication Engineers
Highly reflectiv fiber Bragg gratings formed on high NA dispersion-shifted fibers

Komukai Tetsuro, Nakazawa Masataka

Proceedings of the IEICE General Conference　1996　(2)　741-742　1996/03/11
Publisher: The Institute of Electronics, Information and Communication Engineers
Demultiplexing and routng of 2.5Gbit/s ×4TDM signal using optical fiber gratings

Ymamoto Takashi, Imai Takeshi, Komukai Tetsuro, Nakazawa Masataka

Proceedings of the IEICE General Conference　1996　(2)　745-746　1996/03/11
Publisher: The Institute of Electronics, Information and Communication Engineers
Terabit optical signal demultiplexing with a femtosecond nonlinear fiber loop mirror.

山田英一, 鈴木和宣, 中沢正隆

電子情報通信学会大会講演論文集　1996　(Society C1)　1996

ISSN： 1349-1369
0.5W average power, 10GHz repetition rate femtosecond source in the 1.55.MU.m region.

田村公一, 吉田英二, 山田英一, 中沢正隆

電子情報通信学会大会講演論文集　1996　(Sogo Pt 4)　1996

ISSN： 1349-1369
Evaluation of optical transmission systems using Q-Map. Comparison between Soliton and NRZ and RZ pulse at zero GVD.

佐原明夫, 久保田寛和, 中沢正隆

電子情報通信学会大会講演論文集　1996　(Society C1)　1996

ISSN： 1349-1369
Transmission characteristics of dispersion-averaged solitons.

佐原明夫, 久保田寛和, 中沢正隆

電子情報通信学会大会講演論文集　1996　(Sogo Pt 4)　1996

ISSN： 1349-1369
Marked Increase in the Power Margin Through the Use of a Dispersion-Allocated Soliton.

中沢正隆, 久保田寛和, 佐原明夫

電子情報通信学会大会講演論文集　1996　(Society C1)　1996

ISSN： 1349-1369
Recent Progress in Long-Distance Soliton Communication.

NAKAZAWA Masataka

The Review of Laser Engineering　24　(6)　633-640　1996
Publisher: The Laser Society of Japan
DOI： 10.2184/lsj.24.633 　

ISSN： 0387-0200

eISSN： 1349-6603

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Current progress on long-distance soliton transmission technologies is summarized, in which the use of erbium-doped fiber amplifiers has been a major breakthrough for the soliton communication. Techniques which can send solitons over unlimited distance are described, in which soliton control in time and frequency domains plays an important role as an optical 3R repeater. Finally, a new soliton transmission technique which employs dispersion allocation is described, which enables us to bring the soliton transmission into a developmental stage.
Optical soliton transmission technology

NAKAZAWA Masataka

16　283-287　1996/01/01

ISSN： 0913-6355
Recent Progress in Optical Fiber Bragg Gratings

KOMUKAI Tetsuro, NAKAZAWA Masataka

Technical report of IEICE. OPE　95　(415)　19-24　1995/12/14
Publisher: The Institute of Electronics, Information and Communication Engineers

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Fiber Bragg gratings are being very actively researched because they have potentially important applications in future optical communication systems. Recently, highly controlled high performance gratings have been developed as well as highly reflective gratings. Also, research on their applications to optical networks and all optical processing has started. In this report, we describe the recent progress in optical fiber Bragg gratings focusing on fabrication techniques.
Recent Progress in Optical Fiber Bragg Gratings

KOMUKAI Tetsuro, NAKAZAWA Masataka

Technical report of IEICE. OPE　95　(415)　19-24　1995/12/14
Publisher: The Institute of Electronics, Information and Communication Engineers

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Fiber Bragg gratings are being very actively researched because they have potentially important applications in future optical communication systems. Recently, highly controlled high performance gratings have been developed as well as highly reflective gratings. Also, research on their applications to optical networks and all optical processing has started. In this report, we describe the recent progress in optical fiber Bragg gratings focusing on fabrication techniques.
Recent Progress in Optical Soliton Transmission

NAKAZAWA Masataka

Technical report of IEICE. OCS　95　(272)　43-50　1995/09/28
Publisher: The Institute of Electronics, Information and Communication Engineers

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With a view to realizing Broadband ISDN, it is becoming more important to achieve ultrahigh-speed optical communication systems. One promising approach is the optical soliton communication, which does not change its waveform over long distances. In this paper, we report the recent progress in optical soliton communication including the field demonstration and discuss future prospects for optical soliton technologies.
An in-line fiber grating-type bandpass filter tuned by applying lateral stress

KOMUKAI Tetsuro, YAMAMOTO Takashi, NAKAZAWA Masataka

Proceedings of the Society Conference of IEICE　1995　(1)　148-148　1995/09/05
Publisher: The Institute of Electronics, Information and Communication Engineers
DEMUX and Optical Routing of Highspeed TDM Signals

IMAI Takeyuki, YAMAMOTO Takashi, NAKAZAWA Masataka

Proceedings of the Society Conference of IEICE　1995　(1)　163-163　1995/09/05
Publisher: The Institute of Electronics, Information and Communication Engineers
Nonlinear pulse transmission in an optical fiber with zero-average dispersion

Kubota Hirokazu, Nakazawa Masataka

Proceedings of the Society Conference of IEICE　1995　(1)　272-272　1995/09/05
Publisher: The Institute of Electronics, Information and Communication Engineers
Broad wavelength tunable femtosecond fiber laser

Tamura K.R, Kimura Y., Nakazawa M.

Proceedings of the Society Conference of IEICE　1995　(1)　279-279　1995/09/05
Publisher: The Institute of Electronics, Information and Communication Engineers
Generation of a femtosecond optical pulse train at 20 GHz

Yoshida E., Kimura Y., Nakazawa M.

Proceedings of the Society Conference of IEICE　1995　(1)　280-280　1995/09/05
Publisher: The Institute of Electronics, Information and Communication Engineers
Generation of a tera bit/s optical data pulse train

Yamada E., Yoshida E., Kitoh T., Nakazawa M.

Proceedings of the Society Conference of IEICE　1995　(1)　278-278　1995/09/05
Publisher: The Institute of Electronics, Information and Communication Engineers
10Gbit/s-1,200km dark soliton data transmission

Suzuki K., Nakazawa M.

Proceedings of the Society Conference of IEICE　1995　(1)　276-276　1995/09/05
Publisher: The Institute of Electronics, Information and Communication Engineers
Fiber Lasers

NAKAZAWA Masataka

Appl. Phys. Lett.　24　(7)　398-399　1995/07/10

ISSN： 0389-6625
IN-LINE FIBER GRATING-TYPE OPTICAL BANDPASS FILTER TUNED BY APPLYING LATERAL STRESS (VOL 34, PG L306, 1995)

T KOMUKAI, Y MIYAJIMA, M NAKAZAWA

JAPANESE JOURNAL OF APPLIED PHYSICS PART 2-LETTERS　34　(5B)　L648-L648　1995/05

ISSN： 0021-4922
An in-line optical bandpass filter with fiber gratings and an optical circulator

KOMUKAI Tetsuro, MIYAJIMA Yoshiaki, NAKAZAWA Masataka

Proceedings of the IEICE General Conference　1995　(1)　235-235　1995/03/27
Publisher: The Institute of Electronics, Information and Communication Engineers
Harmonically and regeneratively mode-locked erbium-doped

Yoshida E., Kimura Y., Nakazawa M.

Proceedings of the IEICE General Conference　1995　(1)　397-397　1995/03/27
Publisher: The Institute of Electronics, Information and Communication Engineers
Soliton data transmission using commercially aveilable optical cables

Kubota Hirokazu, Nakazawa Masataka

Proceedings of the IEICE General Conference　1995　(1)　407-407　1995/03/27
Publisher: The Institute of Electronics, Information and Communication Engineers
A subpicosecond demultiplexing at 10 GHz with a Zero-dispersinon, Dispersion-flattened nonlinear fiber loop mirror

YAMADA Eiichi, SUZUKI Kazuroni, NAKAZAWA Masataka

Proceedings of the IEICE General Conference　1995　(1)　408-408　1995/03/27
Publisher: The Institute of Electronics, Information and Communication Engineers
A novel optical soliton communication technique using dispersion allocated optical fiber transmission line

Nakazawa Masataka, Kubota Hirokazu

Proceedings of the IEICE General Conference　1995　(1)　406-406　1995/03/27
Publisher: The Institute of Electronics, Information and Communication Engineers
Optical pass routing adopting wavelength conversion using four-wave mixing and wavelength routing using fiber grating filter

YAMAMOTO Takashi, IMAI Takeshi, KOMUKAI Tetsuro, MIYAJIMA Yoshiaki, NAKAZAWA Masataka

Proceedings of the IEICE General Conference　1995　(1)　312-312　1995/03/27
Publisher: The Institute of Electronics, Information and Communication Engineers
A novel optical soliton communication technique using dispersion allocated optical fiber transmission line.

中沢正隆, 久保田寛和

電子情報通信学会大会講演論文集　1995　(Sogo Pt 4)　1995

ISSN： 1349-1369
Analysis on femtosecond soliton-soliton interaction.

須川智規, 久保田寛和, 中沢正隆

電子情報通信学会大会講演論文集　1995　(Society C1)　1995

ISSN： 1349-1369
Gain characteristics of an ultra-long active transmission line using distributed erbium-doped fiber amplifiers

Kimura Yasuo, Yoshida Eiji, Nakazawa Masataka

1994　(1)　323-323　1994/09/26
Publisher: The Institute of Electronics, Information and Communication Engineers
Recent Progress in Optical Soliton Communication

Nakazawa Masataka

Technical report of IEICE. LQE　94　(228)　25-30　1994/09/13
Publisher: The Institute of Electronics, Information and Communication Engineers

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With a view to realizing Broadband ISDN,it is becoming more important to achieve ultrahigh-speed opticalcommunication systems. One promising approach is the optical soliton communication,which does not change its waveform over long distances.In this paper,we report the recent progress in optical soliton communication using erbium-doped fiber amplifiers and discuss future prospects for optical soliton technologies.We also describe the optical soliton control technology which will be a key technology in all-optical high-speed communication in the future.
Soliton Transmission Control for Long Distance,Ultra High Speed Systems

Kubota Hirokazu, Nakazawa Masataka

Technical report of IEICE. LQE　94　(228)　31-36　1994/09/13
Publisher: The Institute of Electronics, Information and Communication Engineers

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A combination of time and frequency domain control eliminates the noise accumulation and timing jitter caused by soliton interaction and the Gordon-Haus effect,that are the main impediments to extending the transmission distance.We report soliton control techniques applied over 180,000,000 km and the possibility of realizing a sub-tera bit, s soliton transmission system operating over more than 5,000 km in which the soliton self- frequency shift is controlled with the soliton control technique.
Sub-Tera-bit/s soliton transmission that uses soliton control.

久保田寛和, 中沢正隆

電子情報通信学会大会講演論文集　1994　(Shunki Pt 4)　1994

ISSN： 1349-1369
20Gbit/s, 3000km soliton data transmission beyond Gordon-Haus limit.

中沢正隆, 鈴木和宣, 山田英一, 木村康郎

電子情報通信学会大会講演論文集　1994　(Shuki Pt 4)　1994

ISSN： 1349-1369
Ultrahigh-speed optical soliton communication using erbium-doped optical amplifiers.

中沢正隆

電子情報通信学会大会講演論文集　1994　(Shunki Pt 4)　1994

ISSN： 1349-1369
Polarization dependence of soliton-soliton interaction on femtosecond soliton transmission.

須川智規, 黒河賢二, 久保田寛和, 中沢正隆

電子情報通信学会大会講演論文集　1994　(Shuki Pt 4)　1994

ISSN： 1349-1369
Ultra-high speed soliton communication and soliton control.

Kubota Hirokazu, Suzuki Kazunori, Nakazawa Masataka

Technical report of IEICE. OCS　93　(292)　9-16　1993/10/22
Publisher: The Institute of Electronics, Information and Communication Engineers

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Recently soliton transmission has come of age through the use of EDFAs,and the transmission distance has reached the theoretical limit known as the Gordon-Haus limit.This paper describes soliton transmission control technique designed to enable ultra-long distance soliton transmission.Soliton transmission control is realized by employing synchronous modulation which reduces jitter and noise,and an optical bandpass filter which stabilizes the soliton pulse energy.Ultra-long distance soliton transmission experiments confirmed the usefulness of this technique.
Femtosecond fiber laser with an erbium-doped fiber amplifier

Yoshida Eiji, Kimura Yasuo, Nakazawa Masataka

IEICE technical report. EMD　93　(200)　7-12　1993/08/27
Publisher: The Institute of Electronics, Information and Communication Engineers

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The lasing characteristics of an erbium-doped fiber laser with a nonlinear amplifying loop mirror pumped by 1.48μm laser diodes hav e been investigated in detail.A98 fs pulse was obtained at 1.57μm for a pump power of 60mW,Where the repetition rate of output pulses was random.In order to control the pulse repetition rate,a sub ring cavity was attached to the main cavity.Thus,we could succeed in generating a repetition rate controlled femtosecond pulse train at 125 MHz.
Reduction of Amplified Spontaneous Emission Noise from Tramsmitted Soliton Signals using Nonlinear Optical Switching

Yamada Eiichi, Suzuki Kazunori, Nakazawa Masataka

IEICE technical report. EMD　93　(200)　13-18　1993/08/27
Publisher: The Institute of Electronics, Information and Communication Engineers

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A reduction method of amplified spontaneous emission(ASE)noise from erbium-doped fiber amplifiers was proposed by using nonlinear optical switching of a nonlinear amplifying loop mirror(NALM).The technique was successfully applied to the soliton transmission experiment,in which the ASE from concatenated erbium-doped fiber amplifiers in a 10 Gbit, s - 500 km soliton transmission system has been successfully reduced.The ratio of the signal peak to ASE was improved form 17:1 to 25:1.The chirp characteristics of the output pulse from the NALM were also discussed.It is shown that although chirp occurs inevitably in this nonlinear switching, almost transform-limited pulse can be obtained as long as the nonlinear phase difference in the NALM is kept below 0.3π rad.
Soliton transmission with a 100km repeater spacing that uses soliton control.

久保田寛和, 中沢正隆

電子情報通信学会大会講演論文集　1993　(Shuki Pt 4)　1993

ISSN： 1349-1369
A 20Gbit/s, long-distance optical soliton transmission experiment.

山田英一, 鈴木和宣, 中沢正隆

電子情報通信学会大会講演論文集　1993　(Shunki Pt 4)　1993

ISSN： 1349-1369
Establishment of soliton control technique based on the clock extraction.

鈴木和宣, 山田英一, 久保田寛和, 中沢正隆

電子情報通信学会大会講演論文集　1993　(Shunki Pt 4)　1993

ISSN： 1349-1369
Bit-error-rate measurement in 10Gbit/s-one million km soliton transmission using soliton control technique.

中沢正隆, 鈴木和宣, 山田英一, 久保田寛和

電子情報通信学会大会講演論文集　1993　(Shuki Pt 4)　1993

ISSN： 1349-1369
20Gbit/s-1850km and 40Gbit/s-750km soliton data transmission using erbium-doped fiber amplifiers.

鈴木和宣, 山田英一, 久保田寛和, 中沢正隆

電子情報通信学会大会講演論文集　1993　(Shuki Pt 4)　1993

ISSN： 1349-1369
27p-G-1 Ultrafast Optical Soliton Communication

Nakazawa Masataka

1992　(4)　92-94　1992/09/14
Publisher: The Physical Society of Japan (JPS)
A 10Gbit/s-1200km penalty-free optical soliton transmission experiment.

山田英一, 鈴木和宣, 中沢正隆

電子情報通信学会大会講演論文集　1992　(Shuki Pt 4)　1992

ISSN： 1349-1369
Role of narrow band optical filters in ultra-long distance optical soliton communication.

久保田寛和, 中沢正隆

電子情報通信学会大会講演論文集　1992　(Shuki Pt 4)　1992

ISSN： 1349-1369
27p-G-1 Ultrafast Optical Soliton Communication

Nakazawa Masataka

Meeting Abstracts of the Physical Society of Japan　1992.4　92-94　1992
Publisher: The Physical Society of Japan
DOI： 10.11316/jpsgaiyok.1992.4.0_92 　

eISSN： 2433-118X
光ソリトン伝送 (超高速光エレクトロニクスの最前線<特集>) -- (光ソリトン伝送)

中沢正隆

電子情報通信学会論文誌 C-(0xF9C1) エレクトロニクス (0xF9C1)-光・波動　74　(11)　p429-439　1991/11
Publisher: 電子情報通信学会エレクトロニクスソサイエティ
ISSN： 0915-1893
光ソリトン伝送系(長距離光伝送システム) (光ファイバ増幅<特集>) -- (光ファイバ増幅器のシステム応用への展望)

中沢正隆

電子情報通信学会誌　74　(3)　p229-234　1991/03
Publisher: 電子情報通信学会
ISSN： 0913-5693
Erドープ光ファイバによる光増幅器とその応用

中沢正隆

応用物理　59　1175-1175　1991
ファイバ中の光ソリトン通信研究動向

中川清司, 中沢正隆

電子情報通信学会誌　73　(12)　p1336-1343　1990/12
Publisher: 電子情報通信学会
ISSN： 0913-5693
光ファイバによる光増幅

中沢正隆

光学　18　(6)　p291-296　1989/06
Publisher: 応用物理学会分科会日本光学会
ISSN： 0389-6625
光ファイバレ-ザ-

中沢正隆

光学　16　(6)　p256-257　1987/06
Publisher: 応用物理学会分科会日本光学会
ISSN： 0389-6625
Nonlinear Optics in Optical Fibers

NAKAZAWA Masataka

Oyo Buturi　56　(10)　1265-1288　1987
Publisher: The Japan Society of Applied Physics
DOI： 10.11470/oubutsu1932.56.1265 　

ISSN： 0369-8009

eISSN： 2188-2290
Optical pulse compression and soliton lasers.

NAKAZAWA Masataka

The Review of Laser Engineering　15　(11)　869-886　1987
Publisher: The Laser Society of Japan
DOI： 10.2184/lsj.15.869 　

ISSN： 0387-0200

eISSN： 1349-6603

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Recent progress on optical pulse compression techniques, optical solitons, and soliton lasers has been discussed. It is shown that nonlinear pulse propagation in single-mode fibers, which includes self-phase modulation and group velocity dispersion, plays an important role in making linearly chirped rectangular pulses, resuiting in efficient compression with a grating pair. The self steepening effect, a third-order dispersion, and the stimulated Raman scattering, which would deteriorate the compression characteristics, have been discussed in dctail. For a negative GVD region, an optical soliton described with a nonlinear schrodinger equation can be creiatcd by balancing SPM with GVD. A soliton laser by means of a color center Iaser and a fiber Raman soliton laser are discussed in terms of a perturbation theory.

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Books and Other Publications 18

光通信技術の飛躍的高度化－光通信の新たな挑戦－

中沢正隆, 鈴木正敏, 盛岡敏夫

2012/04
光科学研究の最前線2

光科学研究の最前, 編集委員会

JILS　2009/12
フォトニクス基礎

伊藤弘昌

コロナ社　2009/11
Ultrahigh-Speed Optical Transmission Technology

H. G. Weber, M. Nakazawa

Springer　2007/09
超高速ネットワーク技術(分担執筆)

NAKAZAWA Masataka

2000
エルビウム添加光ファイバ増幅器(分担執筆)

NAKAZAWA Masataka

1999
光測定器ガイド(分担執筆)

NAKAZAWA Masataka

1998
応用物理ハンドブック(分担執筆)

NAKAZAWA Masataka

1998
New Trends in Optical Soliton Transmission(Co-author)Systems Kluwer Academic Publishers

NAKAZAWA Masataka

1998
量子工学ハンドブック(分担執筆)

NAKAZAWA Masataka

1997
電子情報通信技術ハンドブック(分担執筆)

NAKAZAWA Masataka

1997
光情報通信ハンドブック(分担執筆)

NAKAZAWA Masataka

1996
固体レーザー日本分光学会測定法シリーズ(分担執筆)

NAKAZAWA Masataka

1993
オプトエレクトロニクス用語辞典オーム社(分担執筆)

NAKAZAWA Masataka

1993
光増幅器とその光通信システムへの応用

NAKAZAWA Masataka

1992
超高速エレクトロニクス(分担執筆)

NAKAZAWA Masataka

1991
超高速光技術(分担執筆)

NAKAZAWA Masataka

1990
レーザーハンドブック(分担執筆)

NAKAZAWA Masataka

1989

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Research Projects 10

多機能なコヒーレントナイキストパルスの提案とそれを用いた超高速・高効率光伝送技術

中沢正隆, 廣岡俊彦, 吉田真人, 葛西恵介

Offer Organization: 日本学術振興会

System: 科学研究費助成事業

Category: 特別推進研究

Institution: 東北大学

2014 - 2018

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本年度はナイキストパルス伝送の高速・大容量化ならびに周波数利用効率(SE : Spectral Efficiency)向上への最終的な取り組みとして、(a)ノンコヒーレントナイキストパルスを用いた単一チャネル10Tbit/s伝送の実現、(b)波長多重ナイキストパルス伝送、ならびに(c)コヒーレントナイキストパルス伝送の単一チャネル15Tbit/sへの高速化・高SE化、の3つに取り組んだ。 (a)に関しては、2.56Tsymbol/sのシンボルレートで単一チャネル10.2Tbit/sの超高速伝送を2.5～3.7bit/s/HzのSEで実現した。10Tbit/sへの高速化にあたり、ノンコヒーレントナイキストパルスの340fsへの超短パルス化、4次分散まで考慮した高次分散補償、ならびに非線形ファイバループミラー(NOLM : Nonlinear Optical Loop Mirror)を用いたゲート幅230fsの超高速光多重分離を実現した。これらの技術を結集し、単一チャネル10.2Tbit/s信号の225km伝送(SE : 3.7bit/s/Hz)および300km伝送(SE : 2.5bit/s/Hz)を達成した。次に(b)に関しては、ナイキストパルスの波長分割多重(WDM : Wavelength Division Multiplexing)への応用を目指して、1チャネルあたり1.28Tbit/sの超高速WDM伝送システムを構築した。この際、光通信用波長帯(Cバンド)で18Tbit/sのWDM信号を僅か14チャネルで生成することにより、1.28Tbits×14波WDM伝送を3.7bit/s/HzのSEで実現した。 (c)に関しては、最終目標であるコヒーレントナイキストパルスを用いた単一チャネル15.4Tbit/s、SE=8.3bit/s/Hzの超高速・高効率伝送に世界で初めて成功した。具体的には、コヒーレントパルスのシンボルレートを1.28Tsymbol/sまで高速化し、64QAM(Quadrature Amplitude Modulation)方式により単一チャネルで10Tbit/sを凌駕する究極的なコヒーレント超高速伝送を実現している。その際、ホモダイン検波回路における自己ビート成分の低減、および多重分離に関与しないトリビュータリを抑制するための光ゲート回路の導入により、ナイキストパルスの高OSNR化を図っている。これらの要素技術により、単一チャンネル15.4Tbit/s-150km超高速コヒーレントナイキストパルス伝送を8.3bit/s/Hzという極めて高いSEで達成した。以上により、ナイキストパルスが高速性と高SE化の両面で極めて優れた伝送性能を有する究極的な光パルスであることを実証することに成功した。
光通信波長帯高精度レーザ歪みセンサの開発

中沢正隆

Offer Organization: 日本学術振興会

System: 科学研究費助成事業

Category: 挑戦的萌芽研究

Institution: 東北大学

2013/04/01 - 2015/03/31

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平成25年度は、光ファイバを用いた津波計測用センサを設計・試作した。従来技術であるファブリー・ペロー共振器の代わりに、ファイバリング共振器を利用した新たなセンサ構造を提案し、その1次試作を行なった。本課題で試作したセンサは、円筒構造（直径120 mm、高さ240 mm）のアルミ材に全長が4.5 mのファイバリング共振器を巻き付けるといった簡便かつ安価な構造を有する。そして、水圧変化に伴うセンサの直径方向の変化量をリング共振器の共振周波数より測定するものである。つぎに試作したセンサと2台の周波数可変ファイバレーザを組み合わせることにより、レーザ津波計を作製し、水槽を利用した水位変化量の計測を実施した。2台のレーザを利用することにより温度変動に伴う測定誤差を50分の1に低減することに成功した。このような条件のもと、水槽の水位を約1 cmずつ変化させていった際に、12.2 MHz/cmというビート周波数の検出感度を得た。ビート信号の短期的なスペクトル揺らぎ（±110 kHz）から算出される水位変化量の測定誤差は90μmであり、世界最高水準の性能を実現することに成功した。平成26年度は、平成25年度に試作した津波計測用センサの感度向上を目指し、圧力により形状変化が起こり易い凹凸構造を設けたセンサ部を新たに試作した。また、120度ずつ角度のずれた方向に歪み検出用センサ部を設けた三成分歪み計測用センサを試作した。しかし、平成26年度に新規に採択された特別推進研究課題との重複の制限により、試作したセンサの評価ならびに改良を課題として残した状況で本課題が終了することになった。本研究は大震災への対策技術として、地殻変動に伴う歪み量の高感度計測ならびに津波計測にとって大変重要である。今後も本研究を継続していく予定である。研究発表：JAMSTEC連携協定協議会「高感度レーザ津波センサの試作」
GHz mode-locked pulse laser with simultaneously stabilized optical frequency and repetition rate and its applications

NAKAZAWA MASATAKA, YOSHIDA Masato

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research

Category: Grant-in-Aid for Scientific Research (S)

Institution: Tohoku University

2009/05/11 - 2014/03/31

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We have demonstrated for the first time a mode-locked pulse laser with simultaneo-usly stabilized optical frequency and repetition rate by using a Cs atomic resonance and an acetylene mol-ecular absorption line, respectively. We also successfully demonstrated a 440 fs short pulse generation byemploying a saturable absorber in the laser cavity for narrowing the pulse width. Furthermore,we applied apulse source based on a frequency stabilized CW laser to coherent optical pulse transmission, and we have successfully demonstrated for the first time a 1.92 Tbit/s single channel transmission with 64 QAM signal.
カーボンナノチューブを用いたフェムト秒レーザおよび超高速光スイッチ素子の研究

中沢正隆

Offer Organization: 日本学術振興会

System: 科学研究費助成事業

Category: 基盤研究(A)

Institution: 東北大学

2009 - 2009
Establishment of novel ultrahigh-speed distortion-free optical transmission technology using time-domain optical Fourier transformation

NAKAZAWA Masataka, HIROOKA Toshihiko, YOSHIDA Masato

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research

Category: Grant-in-Aid for Specially Promoted Research

Institution: Tohoku University

2004 - 2008
GHz帯高安定パルスレーザを用いた新たなCs光原子時計に関する研究

中沢正隆

Offer Organization: 日本学術振興会

System: 科学研究費助成事業

Category: 基盤研究(A)

Institution: 東北大学

2004 - 2004
Ultrashort mode-locked lasers and their applications to frequency standard and opto-microwave area Competitive

2001/04 -
Terabit/s OTDM transmission using a femtosecond pulse train Competitive

2001/04 -
Ultrahigh-speed optical soliton transmission and nonlinear optics in fibers Competitive

2001/04 -
GENERATION OF FEMTOSECOND OPTICAL PULSES BY COMPRESSION OF LINAC CERENKOV RADIATION PULSE

KOBAYASHI Tetsuro, NAKAZAWA Masataka, KAMIYA Takeshi, OWAKI Shigehiro, CHO Yoshio, SHIMODA Koichi

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research

Category: Grant-in-Aid for Co-operative Research (A)

Institution: OSAKA UNIVERSITY

1990 - 1992

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The purposes of this study are to improve the temporal and spatial coherence of Cerenkov Radiation (CR) and to develop new coherent light source such as Laser light, and to find out the generation method of ultimately short optical pulses applying ultrashort laser pulse techniques to broadband CR. First of all, possibility of femtosecond CR pulse generation by compensation of group velocity dispersion of CR dielectric was shown analytically and a femtosecond CR pulse generation system was designed with micro-bunching by a laser accelerator(1991, JPSJ). The near field of dipole radiation which is closely related to CR has been analyzed (by Shimoda). Two types of novel FIR generators using coherent CR were proposed. They employ laser/ photocathode electron sources and hollow dielectric Cerenkov radiators with high refractive index, one can generate a MW monocycle pulse and the other a tunable monochromatic light efficiently (by Kobayashi). Owaki, Sugihara, and Kimura studied 10-20ps white CR pulses and found one kind of coherent radiation in the mm-wavelength region. Kamiya proposed novel measurement method of white ultrashort pulses with compensation of the electron transit time and confirmed its function experimentally with photodetector-sequence. Cho invented time-resolvable nonlinear convolution spectrometer which is also useful for pulse measurement. Nakazawa studied various kinds of pulse compression methods applicable for CR pulses and propagation of CR pulse in velocity dispersion media and gain media.

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