TSUDA Hiroyuki



Faculty of Science and Technology, Department of Electronics and Electrical Engineering Department of Electronics and Electrical Engineering, Faculty of Science and Technology (Yagami)



E-mail Address

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Profile Summary 【 Display / hide

Career 【 Display / hide

  • 2000.04


  • 2001.04


  • 2007.04


  • 2018.09

    University College London, Optical Networks Group, Visiting Professor

  • 2020.04

    Department of Electronics and Electrical Engineering, Faculty of Science and Technology, Keio University

Academic Background 【 Display / hide

  • 1985.03

    Waseda University, Faculty of Science and Engineering

    University, Graduated

  • 1987.03

    Tokyo Institute of Technology, Graduate School, Division of Integrated Science an, 物理情報工学専攻

    Graduate School, Completed, Master's course

Academic Degrees 【 Display / hide

  • Ph.D. in Engineering, Tokyo Institute of Technology, Dissertation, 1998.02


Research Areas 【 Display / hide

  • Optical engineering, Photon science (Applied Optics/Quantum Optical Engineering)

  • Electron device/Electronic equipment (Electronic Device/Electronic Equipment)

  • Communication/Network engineering (Communication/Network Engineering)

Research Keywords 【 Display / hide

  • Photonic Network

  • Optical Signal Processing

  • Optical Waveguide

  • Opitical Communication

Research Themes 【 Display / hide

  • ロボットフォトニクス, 


  • Automotive Optical Network, 


  • Wavelength Selective Switch, 


  • Optical Switch Using Phase-Change Material, 


  • Optical Signal Processing Using Arrayed-Waveguide Grating, 



Papers 【 Display / hide

  • Guanine crystals regulated by chitin-based honeycomb frameworks for tunable structural colors of sapphirinid copepod, Sapphirina nigromaculata

    Kimura T., Takasaki M., Hatai R., Nagai Y., Uematsu K., Oaki Y., Osada M., Tsuda H., Ishigure T., Toyofuku T., Shimode S., Imai H.

    Scientific Reports (Scientific Reports)  10 ( 1 )  2020.12

     View Summary

    © 2020, The Author(s). Sapphirinid copepods, which are marine zooplankton, exhibit tunable structural colors originating from a layered structure of guanine crystal plates. In the present study, the coloring portion of adult male of a sapphirinid copepod, Sapphirina nigromaculata, under the dorsal body surface was characterized to clarify the regulation and actuation mechanism of the layered guanine crystals for spectral control. The coloring portions are separated into small domains 70–100 µm wide consisting of an ordered array of stacked hexagonal plates ~1.5 µm wide and ~80 nm thick. We found the presence of chitin-based honeycomb frameworks that are composed of flat compartments regulating the guanine crystal plates. The structural color is deduced to be tuned from blue to achromatic via yellow and purple by changing the interplate distance according to vital observation and optical simulation using a photonic array model. The framework structures are essential for the organization and actuation of the particular photonic arrays for the exhibition of the tunable structural color.

  • S-, C- And L-Band Photonic Integrated Wavelength Selective Switch

    Kraemer R., Nakamura F., Tsuda H., Napoli A., Calabretta

    2020 European Conference on Optical Communications, ECOC 2020 (2020 European Conference on Optical Communications, ECOC 2020)   2020.12

    ISSN  9781728173610

     View Summary

    A photonic integrated WSS operating on the S-, C- and L-Band is presented with an average extinction-ratio of -20.40 dB. Crosstalk levels were kept below -20 dB for all bands and experimental results on NRZ OOK data indicate error-free operation for up to 35 Gb/s.

  • Silicon photonics platforms for optical communication systems, outlook on future developments

    Tsuda H.

    IEICE Electronics Express (IEICE Electronics Express)  17 ( 22 ) 1 - 7 2020.11

    ISSN  13492543

     View Summary

    This paper reviews recent progress in silicon photonics and compares it with other optical device platforms. The key components for optical communication systems, including arrayed waveguide gratings, optical switches, modulators and optical functional devices fabricated on silicon photonics platforms are explained. The integration of III-V compounds, lithium niobate, polymers, phase change and other functional materials are necessary to strengthen silicon photonics platforms. These are also reviewed, and the feasibilities are discussed. Finally, I express my personal view as to the best research direction for silicon photonics.

  • High extinction ratio and low crosstalk C and L-Band photonic integrated wavelength selective switching

    Kraemer R.M.G., Nakamura F., Wang Y., Tsuda H., Calabretta N.

    International Conference on Transparent Optical Networks (International Conference on Transparent Optical Networks)  2020-July 2020.07

    ISSN  9781728184234

     View Summary

    A photonic integrated 1×2 Wavelength Selective Switch (WSS) based on a loopback configuration is shown to operate on the C and L-Bands due to the cyclic nature of the employed arrayed-waveguide gratings (AWGs). An average of -22.59 dB and -20.40 dB were observed in the C and L-band channels respectively. Crosstalk levels are kept below -40 dB on the output port A and below -30 dB on output port B. Experimental results on NRZ OOK data indicate a bit-error-rate (BER) below 1×10-11 with very limited penalty at both bands up to a bit rate of 30 Gbps.

  • Silicon Based 1 × M Wavelength Selective Switch Using Arrayed Waveguide Gratings with Fold-Back Waveguides

    Nakamura F., Asakura H., Suzuki K., Tanizawa K., Ohtsuka M., Yokoyama N., Matsumaro K., Seki M., Ikeda K., Namiki S., Kawashima H., Tsuda H.

    Journal of Lightwave Technology (Journal of Lightwave Technology)  39 ( 8 ) 2413 - 2420 2020.04

    ISSN  07338724

     View Summary

    The design of a novel 1 × M fold-back type wavelength selective switch (WSS), which has fewer waveguide crossings than a conventional integrated WSS, is reported. The WSS is composed of interleavers, 1 × M optical switches, and arrayed waveguide gratings (AWGs). Switches are combined with AWGs by fold-back waveguides, and each AWG works as both a demultiplexer and multiplexer thus avoiding center wavelength mismatch caused by fabrication errors. Waveguide crossings cause excess crosstalk and loss in lightwave circuits. By using a fold-back architecture the number of crossings can be reduced to less than half that of a conventional design. We discuss the operating principle, the design method, and the scalability of the fold-back type WSS. Furthermore, the switching operation of a 200-GHz spacing, 20-channel, 1 × 2 silicon WSS in a fold-back configuration on a 5 mm × 10 mm SOI chip is demonstrated. This has 15 waveguide crossings in a path, of which six are additional crossings with monitor waveguides. The average insertion loss and average extinction ratio are 29.6 dB and 10.9 dB, respectively.

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Papers, etc., Registered in KOARA 【 Display / hide

Presentations 【 Display / hide

  • Proof-of-Principle Frequency-Bin Quantum Key Distribution with Biphoton Frequency Combs

    Murat Can Sarihan, Kai-Chi Chang, Xiang Cheng, Hiroyuki Tsuda, Chee Wei Wong

    CLEO 2021 (U. S. A.) , 2021.05, Oral Presentation(general)

  • Study of a demultiplexing scheme for mode multiplexed signals using neural network signal processing

    Naoya Takahashi and Hiroyuki Tsuda

    2020 International Conference on Emerging Technologies for Communications (Tokyo, Japan) , 2020.12, Oral Presentation(general)

  • Experimental Assessments of a Flexible Optical Data Center Network Based on Integrated Wavelength Selective Switch

    X. Xue, F. Nakamura, K. Prifti, B. Pan, F. Yan, F. Wang, X. Guo, H. Tsuda, and N. Calabretta

    Optical Fiber Communication Conference (OFC) 2020 (U. S. A.) , 2020.03, Oral Presentation(general)

  • FMCW LiDAR Detection System Optimized for Reducing the Effect of Speckles on the Detector Aperture

    Shun Ishikura, Andrea Zirotti, and Hiroyuki Tsuda

    Photonics Device Workshop (Tokyo, Japan) , 2019.12, Poster (general)

  • Effect of Se addition to Ge2Sb2Te5 on optical constants

    Kenta Sakamoto, Masashi Kuwahara, Rie Endo and Hiroyuki Tsuda

    The Symposium on Phase Change Oriented Science (PCOS) 2019 (Shizuoka, Japan) , 2019.11, Oral Presentation(general)

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Research Projects of Competitive Funds, etc. 【 Display / hide

  • 低電力再構成可能フォトニックネットワークに向けた相変化光スイッチの研究


    MEXT,JSPS, Grant-in-Aid for Scientific Research, 津田 裕之, Grant-in-Aid for Scientific Research (B), Principal Investigator

  • 高度自動運転に向けた大容量車載光ネットワーク基盤技術の研究開発


    Commissioned research, Principal Investigator

  • 大規模光ネットワーク構成に向けた相変化型省電力光スイッチの研究


    MEXT,JSPS, Grant-in-Aid for Scientific Research, 津田 裕之, Grant-in-Aid for Scientific Research (B), Principal Investigator

Intellectual Property Rights, etc. 【 Display / hide

  • 波長クロスコネクト装置

    Application No.: 特願2012-090182  2012.04 

    Registration No.: 5692865 

    Patent, Joint

Awards 【 Display / hide

  • ELEX Best Paper Award in the year 2018

    Fumi Nakamura, Hideaki Asakura, Keijiro Suzuki, Ken Tanizawa, Minoru Ohtsuka, Nobuyuki Yokoyama, Kazuyuki Matsumaro, Miyoshi Seki, Keiji Koshino, Kazuhiro Ikeda, Shu Namiki, Hitoshi Kawashima, and Hiroyuki Tsuda, 2019.09, IEICE Electronics Society, Silicon photonics based 1×2 wavelength selective switch using fold-back arrayed-waveguide gratings

    Type of Award: Celebration by Official journal of a scientific society or Academic Journal

  • PCOS 2014 Best Paper Award

    Hiroyuki Tsuda, Takumi Moriyama, Yasuro Shimazaki, Masashi Kuwahara, Xiaomin Wang, and Hitoshi Kawashima, 2014.12, The Society of Phase Change Oriented Science, Mach-Zehnder Interferometer Type Optical Switch Using Phase-Change Material

    Type of Award: Awards of National Conference, Council and Symposium

  • IEICE Electronics Express Best Paper Award in the year 2005

    TSUDA HIROYUKI, 2006.05, 電子情報通信学会エレクトロニクスソサイエティ, T. Suzuki, K. Masuda, H. Ishikawa, Y. Abe, S. Kashimura, H. Uetsuka and H. Tsuda, “Planar lightwave circuit dispersion compensator using a compact arrowhead arrayed-waveguide grating,” IEICE Electronics Express, Vol. 2, No. 23, pp. 572-577(2005).

    Type of Award: Awards of National Conference, Council and Symposium


Courses Taught 【 Display / hide











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Courses Previously Taught 【 Display / hide

  • 電気回路基礎

    Keio University, 2017, Spring Semester, Major subject, Lecture

  • Optical Network System

    Keio University, 2017, Autumn Semester, Major subject

  • コミュニケーションシステム

    Keio University, 2017, Autumn Semester, Major subject, Lecture

  • 光デバイス工学

    Keio University, 2017, Autumn Semester, Major subject, Lecture

  • Optical Network System

    Keio University, 2016, Autumn Semester, Major subject, Lecture, Within own faculty, 20people

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Memberships in Academic Societies 【 Display / hide

  • IEEE Comsoc, 

  • IEEE Photonics Society, 

  • 日本光学会, 

  • 電子情報通信学会, 

  • The Optical Society, 


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Committee Experiences 【 Display / hide

  • 2020.06

    President of the IEICE Electronics Society, Institute of Electronics, Information and Communication Engineers

  • 2019.06

    エレクトロニクスソサエティ 次期会長, 電子情報通信学会

  • 2019.04

    代表幹事, 光ネットワーク産業・技術研究会

  • 2017.06

    エレクトロニクスソサエティ ソサイエティ副会長(編集出版担当), 電子情報通信学会

  • 2013.04

    Adviser, 電子情報通信学会エレクトロニクスソサエティ レーザ・量子エレクトロニクス研究専門委員会

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