Ishigure, Takaaki



Faculty of Science and Technology, Department of Applied Physics and Physico-Informatics (Yagami)



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Career 【 Display / hide

  • 1996.04

    財団法人神奈川科学技術アカデミー ,研究員

  • 1998.04


  • 2001.04

    慶應義塾大学理工学部 ,助手

  • 2003.04


  • 2005.01

    コロンビア大学 電気工学科 訪問研究員

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Academic Background 【 Display / hide

  • 1991.03

    Keio University, Faculty of Science and Engineering, 応用化学科

    University, Graduated

  • 1993.03

    Keio University, Graduate School, Division of Science and Engineeri, 物質科学専攻

    Graduate School, Completed, Master's course

  • 1996.03

    Keio University, Graduate School, Division of Science and Engineeri, 物質科学専攻

    Graduate School, Completed, Doctoral course

Academic Degrees 【 Display / hide

  • 工学, Keio University, 1996.03


Research Themes 【 Display / hide

  • Polymer Optical Waveguide for Optical Interconnection, 



Books 【 Display / hide

  • 科学立国日本を築くPartⅡ 次代を拓く気鋭の研究者たち

    一般財団法人丸文財団選考委員会 (編集) 榊 裕之 (監修) (分担) 石榑 崇明, 日刊工業新聞社, 2017.03

    Scope: ポリマ光導波路の低分散化と光インターコネクションへの応用

  • 光インターコネクションの第二普及世代に向けた課題と予測 (光回路実装技術ロードマップ2016年度版)

    ISHIGURE TAKAAKI, エレクトロニクス実装学会光回路実装技術委員会, 2017.02

    Scope: 121-134

  • Optical Interconnects for Data Centers

    Takaaki Ishigure and Marika Immonen, Woodhead Publishing, 2016.11

    Scope: Chapter 7, Design and fabrication of multimode polymer waveguides for optical interconnects

  • 光インターコネクションの普及とさらなる進展 (光回路実装技術ロードマップ2013年度版)

    ISHIGURE TAKAAKI, エレクトロニクス実装学会光回路実装技術委員会, 2014.01

    Scope: 66-75

  • O Plus E

    ISHIGURE TAKAAKI, アドコム・メディア株式会社, 2011.03

    Scope: 370-375

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Papers 【 Display / hide

  • Mosquito method based polymer tapered waveguide as a spot size converter

    Kobayashi Y., Sakaguchi Y., Yasuhara K., Ishigure T.

    Optics Express (Optics Express)  29 ( 6 ) 9513 - 9531 2021.03

     View Summary

    We create a compact low-loss spot-size converter (SSC) which utilizes a tapered core polymer optical waveguide with circular cross-sectional graded-index (GI) core using the Mosquito method we developed. First, we theoretically analyze the mutual diffusion between the core and cladding monomers, which is a feature unique to the Mosquito method when forming GI cores. The monomer diffusion effect depends on the initial core diameter that is dispensed by a microdispenser and the diffusion time before UV curing: in a small core the monomer diffuses more rapidly than in a large core. Using this diffusion dependence on the initially dispensed core diameter, it is theoretically found that a tapered polymer waveguide based SSC can adiabatically convert the mode-field diameter between 4.0 and 8.6 µm at a 1550-nm wavelength waveguide as short as 4 mm. Next, the tapered waveguide based SSC with the designed structure is experimentally fabricated using the Mosquito method, and we confirm an 8-mm long tapered waveguide with an insertion loss of 1.83dB functions as a SSC that converts the MFD from 4.7 µm to 7.5 µm at 1550-nm wavelength.

  • Low loss single-mode polymer optical waveguide with circular cores

    Yakabe S., Kobayashi Y., Matsui H., Saito Y., Manabe K., Ishigure T.

    OSA Continuum (OSA Continuum)  4 ( 3 ) 1070 - 1085 2021.03

     View Summary

    We experimentally demonstrate that the Mosquito method is capable of fabricating single-mode polymer optical waveguides with multiple cores while maintaining an identical mode-field diameter among them. The Mosquito method we developed is a technique to form circular cores in polymer waveguides using a commercially available microdispenser and multi-axis syringe scanning robot. However, the core shape tends to deteriorate from a circle because of the monomer flow due to the needle scan. We also demonstrate both theoretically and experimentally for the first time in this paper that the needles with a tapered outer form or just titled straight needles enable to form cores with a high circularity even if those cores are dispensed on any heights from the substrate surface.

  • Multi-Channel Single-Mode Polymer Waveguide Fabricated Using the Mosquito Method

    Yakabe S., Matsui H., Kobayashi Y., Saito Y., Manabe K., Ishigure T.

    Journal of Lightwave Technology (Journal of Lightwave Technology)  39 ( 2 ) 547 - 556 2021.01

    ISSN  07338724

     View Summary

    We experimentally demonstrate that the Mosquito method is capable of fabricating polymer optical waveguides with single-mode cores. The Mosquito method we developed is a technique to form planar polymer waveguides using a commercially available microdispenser. In this article, the flow of the core monomer dispensed from the tip of the needle is simulated using fluid analysis software. The results show that the shape of the needle periphery significantly affects the fabrication of perfectly circular cross-sectional cores. In addition, we demonstrate that the Mosquito method is capable of reducing the MFD variation to 0.4 μm. We find such a small MFD fluctuation is comparable to that of typical single-mode optical fibers.

  • 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.

  • Polarization Dependence of Optical Properties of Single-Mode Polymer Optical Waveguides Fabricated under Different Processes at 1310/1550 nm

    Morimoto Y., Matsui H., Hikita M., Ishigure T.

    Journal of Lightwave Technology (Journal of Lightwave Technology)  38 ( 14 ) 3670 - 3676 2020.07

    ISSN  07338724

     View Summary

    We experimentally investigate the polarization dependence of the optical properties of single-mode polymer optical waveguides. We compare two types of waveguides composed of the same polymer materials: Step-index square-core waveguides fabricated using the direct curing method and graded-index (GI) circular-core waveguides fabricated using the Mosquito method. We demonstrate that the GI circular-core single-mode waveguides exhibit remarkably small dependence of optical loss on the polarization angle, which is less than 0.1 dB polarization dependent loss (PDL) at both 1310 and 1550 nm wavelengths. This steady polarization property is attributed to the material stress free to the composing polymers during the fabrication process of the Mosquito method and to parabolic GI profile formed in symmetric circular core.

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

Reviews, Commentaries, etc. 【 Display / hide

  • ポリマー光導波路の研究開発動向

    石榑 崇明

    エレクトロニクス実装学会誌 (一般社団法人 エレクトロニクス実装学会)  20 ( 5 ) 271 - 277 2017.09

    Article, review, commentary, editorial, etc. (scientific journal)

  • なんでモスキート??


    応用物理 (応用物理学会)  86 ( 7 ) 599 - 602 2017.07

    Article, review, commentary, editorial, etc. (other)

  • ポリマー光導波路

    石榑 崇明

    光技術コンタクト (日本オプトメカトロニクス協会)  55 ( 5 ) 10 - 17 2017.05

    Article, review, commentary, editorial, etc. (trade magazine, newspaper, online media), Single Work,  ISSN  0913-7289

  • 3D high-density channel integration of a polymer optical waveguide using the Mosquito method

    Takaaki Ishigure, Daisuke Suganuma, Kazutomo Soma

    Chip Scale Review (Haley Publishing Inc)  19 ( 4 ) 32 - 35 2015.08

    Article, review, commentary, editorial, etc. (scientific journal),  ISSN  1526-1344

     View Summary

    This article includes the review of a conference paper presented at ECTC 2014, which received the outstanding session paper award.

Presentations 【 Display / hide

  • Accurate Core Alignment for Polymer Optical Waveguide in the Mosquito Method for High-Efficient Coupling

    Yoshie Morimoto,Kumi Date,and Takaaki Ishigure

    IEEE 68th Electronic Components and Technology Conference (San Diego, CA, USA) , 


    Poster presentation, IEEE Electronics Packaging (EP) Society

  • Direct Fabrication for Polymer Optical Waveguide in PMT Ferrule Using the Mosquito Method

    Takaaki Ishigure, Hikaru Masuda,Kumi Date,Chinami Marushima. Tadayuki Enomoto

    IEEE 68th Electronic Components and Technology Conference (San Diego, CA, USA) , 


    Oral presentation (general), IEEE Electronics Packaging (EP) Society

  • Multimode / Single-mode Polymer Waveguides for Optical Wiring from the Chip to On-Board

    Takaaki Ishigure

    2018 International Conference on Electronics Packaging and iMAPS All Asia Conference (ICEP-IAAC2018) (Mie, Japan) , 


    Oral presentation (invited, special)

  • 広帯域・高密度オンボード光配線のためのポリマー光導波路

    石榑 崇明

    電子情報通信学会2018総合大会 (東京) , 


    Oral presentation (invited, special)

     View Summary


  • 屈折率分布型ポリマー光導波路のマルチモードファイバ−光源間結合素子への応用


    第32回エレクトロニクス実装学会講演大会 (野田市,千葉) , 


    Oral presentation (general), 一般社団法人 エレクトロニクス実装学会

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

  • Research on high-density 3-dimensional polymer optical waveguide device for photonics-electronics convergence


    基盤研究(B), Principal investigator

Awards 【 Display / hide

  • 2017年度 エレクトロニクスソサイエティ活動功労表彰

    石榑崇明, 2018.03, 一般社団法人 電子情報通信学会 エレクトロニクスソサイエティ, 光エレクトロニクス研究専門委員会幹事としての貢献

  • エレクトロニクス実装学会春季講演大会 講演大会優秀賞

    増田輝,中條徳男,石榑崇明, 2018.03, 一般社団法人 エレクトロニクス実装学会, 多段光デバイスとの接続に向けたオンボード3次元Fan-in/out導波路の作製

  • The 64th Electronic Components and Technology Conference, Outstanding Oral Session Paper Award

    Takaaki Ishigure, Daisuke Suganuma, and Kazutomo Soma, 2015.05, IEEE CPMT, Three-Dimensional High Density Channel Integration of Polymer Optical Waveguide Using the Mosquito Method

    Country: United States

     View Description

    第64回ECTC2014にて口頭発表した論文「Three-Dimensional High Density Channel Integration of Polymer Optical Waveguide Using the Mosquito Method」に対して授与された.

  • The 61st Electronic Components Technology Conference (ECTC 2011) Outstanding Poster Paper Award

    Takaaki Ishigure, Ryota Ishiguro, Hisashi Uno, Hsiang-Han Hsu, 2012.05, IEEE CPMT Society, Maximum channel density in multimode optical waveguides for parallel interconnection

  • 丸文研究奨励賞

    ISHIGURE TAKAAKI, 2008.03, ポリマー光ファイバ・導波路の低損失・低分散化と超高速光インターコネクションへの応用に関する研究

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Courses Taught 【 Display / hide











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Social Activities 【 Display / hide

  • Japan Science and Technology Corpoation ERATO

  • 通産省 「情報家電機器間の相互接続正確保のための標準化」委員会


Memberships in Academic Societies 【 Display / hide

  • 応用物理学会分科会 フォトニクス分科会, 

  • 応用物理学会分科会 日本光学会, 

  • The 18th OptoElectronics and Communications Conference (OECC2013) / Photonics in Switching 2013 (PS2013), 

  • 電子情報通信学会 光エレクトロニクス(OPE)研究専門委員会, 

  • Japan Institute of Electronics Packaging, 


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Committee Experiences 【 Display / hide

  • 2020.06

    副委員長, 電子情報通信学会 光エレクトロニクス(OPE)研究専門委員会

  • 2020.05

    光回路実装技術委員会 委員, エレクトロニクス実装学会

  • 2018.11

    The General Chair, IEEE CPMT Symposium JAPAN (ICSJ2019)

  • 2018.05

    編集出版会議 庶務・財務幹事, 電子情報通信学会 エレクトロニクスソサイエティ

  • 2018.05

    光回路実装技術委員会 委員長, エレクトロニクス実装学会

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