Presentations -

ポリマー光導波路：モスキート法による新たな光配線の可能性

ISHIGURE TAKAAKI

電子情報通信学会2016総合大会 (福岡) , 

2016.03

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Oral presentation (invited, special)

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本稿では，近年のポリマー光導波路に関する新たなる開発動向を概観するとともに，我々が注力する新たなポリマー光導波路の作製手法「モスキート法」について紹介し，このモスキート法により可能になる，新しい光回路，光配線のあり方について展望する．

Eu-Alポリマーコンポジット添加光導波路の作製と小型光増幅デバイスへの応用

三谷真利奈，山下兼一，三木　瞳・福井 俊巳，石榑 崇明

電子情報通信学会2016総合大会 (福岡) , 

2016.03

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Oral presentation (general)

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希土類イオンを高濃度添加するために株式会社KRIにより開発されたEuropium-Aluminum（Eu-Al）ポリマーコンポジットを用いてポリマー光導波路を作製し，その発光特性を調べた．作製にはディスペンサを用いたMosquito法を採用し，直径109 umの円形コア光導波路を得た．作製された光導波路に対し，532-nm DPSSレーザと617-nm LEDを用いてCo-axial励起を行い，誘導放出光強度を測定した，励起光強度と信号光強度を変化させ効果的に誘導放出を起こすための最適値を検討したところ，微弱信号光と高強度の励起光に対して利得が増大し，導波路長3.7 cmのEu添加光導波路にて最大10.18 dBの光増幅を確認した．

受動モード同期デバイスへ向けたカーボンナノチューブドープポリマー光導波路

Sho Yoshida，Weijian Ni，Sze Y. Set，Shinji Yamashita, and Takaaki Ishigure

電子情報通信学会光エレクトロニクス(OPE)研究会 (那覇市，沖縄) , 

2016.02

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Oral presentation (general)

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Carbon nanotubes (CNTs) are known to possess a high saturable absorption property and an ultrafast femto-second recovery time. They have been applied successfully as passive mode-locking devices for ultrashort pulse fiber lasers. In our previous research, a passive mode-locking device using a tapered fiber embedded in a CNT/polymer composite was investigated. However, the structure of tapered fiber has issues: the mechanical strength and the reproducibility are low. In this work, a polymer waveguide passive mode-locking device is fabricated by applying the “Mosquito” method. The device offers several advantages, such as (a) good connectivity with a ring cavity-type laser (b) high mechanical strength.

モスキート法を用いた端面研磨フリー円形GI型ポリマー光導波路の作製

Tadayuki Enomoto and Takaaki Ishigure

電子情報通信学会光エレクトロニクス(OPE)研究会 (那覇市，沖縄) , 

2016.02

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Oral presentation (general)

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In this paper, we fabricate graded index (GI) circular core polymer optical waveguides using the Mosquito method, and demonstrate smooth end facets of waveguides without cutting and polishing processes in order to realize direct integration of the polymer waveguide devices on PCBs. We confirm that the insertion loss of the fabricated 5-cm long waveguide is as low as 0.79 dB at 850-nm wavelength.

Planar polymer and glass graded index waveguides for data centre applications

Richard C. Pitwon,Akira Yamauchi,Lars Brusberg, Kai Wang, Takaaki Ishigure,Henning Schröder,and Alex Worrall

SPIE Photonics WEST 2016 OPTO (San Francisco, California, United States) , 

2016.02

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Oral presentation (general)

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Embedded optical waveguide technology for optical printed circuit boards (OPCBs) has advanced considerably over the past decade both in terms of materials and achievable waveguide structures. Two distinct classes of planar graded index multimode waveguide have recently emerged based on polymer and glass materials. We report on the suitability of graded index polymer waveguides, fabricated using the Mosquito method, and graded index glass waveguides, fabricated using ion diffusion on thin glass foils, for deployment within future data center environments as part of an optically disaggregated architecture. To this end, we first characterize the wavelength dependent performance of different waveguide types to assess their suitability with respect to two dominant emerging multimode transceiver classes based on directly modulated 850 nm VCSELs and 1310 silicon photonics devices. Furthermore we connect the different waveguide types into an optically disaggregated data storage system and characterize their performance with respect to different common high speed data protocols used at the intra and inter rack level including 10 Gb Ethernet and Serial Attached SCSI.

Low-loss optical coupling between waveguide and optical modules via 45-degree mirrors realized with grade-index core structure

Yoshie Morimoto, Takaaki Ishigure

SPIE Photonics WEST 2016 OPTO (San Francisco, California, United States) , 

2016.02

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Oral presentation (general)

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In this paper, we theoretically analyze the optical loss in multimode waveguides based optical links including optical path conversion via a 45-degree mirror using a ray-trace simulator. We focus on some waveguide structural parameters: the cladding thickness, the core size, and the refractive index of the core and cladding material, and confirm the optimum waveguide parameters for GI circular-core waveguides for realizing low-loss light coupling. In addition, we experimentally investigate the optical loss of GI circular-core polymer optical waveguides fabricated using the Mosquito method. The fabricated waveguide exhibits low optical insertion loss and low inter-channel crosstalk even after mirror fabrication on its one end.

Densely-aligned multilayered polymer optical waveguide with low interchannel crosstalk

Yusuke Kogo and Takaaki Ishigure

SPIE Photonics WEST 2016 OPTO (San Francisco, California, United States) , 

2016.02

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Oral presentation (general)

Low-loss polymer optical waveguides with graded-index perfect circular cores for on-board interconnection

Yuki Saito and Takaaki Ishigure

SPIE Photonics WEST 2016 OPTO (San Francisco, California, United States) , 

2016.02

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Oral presentation (general)

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Using the Mosquito method, we fabricate low-loss multimode polymer optical waveguides with graded-index (GI) perfect circular cores for the applications to on-board optical interconnection. Originally we used siloxane based monomers. In this paper, novel organic-inorganic hybrid materials (SUNCONNECT®) are selected to confirm the applicability of wide-range polymers to the Mosquito method. Here, a dip is observed on the upper perimeter of the obtained core cross-sections particularly when using a straight needle with a wall-thickness of more than 75 m. Such a core-shape deformation increases the coupling loss with circular-core optical fibers. So, the flow of core and cladding monomers while dispensing the core with the needle scan is visually observed. It is confirmed that the edge of the straight needle chips off the upper perimeter of the core when the core monomer is dispensed, leading to the dip. Therefore, the straight needle is replaced for a curved one to change the dispensing direction for eliminating the dip. Finally, we successfully demonstrate a 1.65-dB lower loss in a 5-cm long waveguide compared to the one having the core with a dip.

Low-Loss Graded Index Multimode Polymer Crossed Waveguides Fabricated Using the Imprint Method

Yutaro Oizumi and Takaaki Ishigure

SPIE Photonics WEST 2016 OPTO (San Francisco, California, United States) , 

2016.02

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Oral presentation (general)

高密度多層GI型円形コアポリマー並列光導波路

Kyuta Suzuki and Takaaki Ishigure

電子情報通信学会光エレクトロニクス(OPE)研究会 (金沢市，石川) , 

2015.12

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Oral presentation (general)

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We have reported a fabrication technique for multimode GI circular-core polymer parallel optical waveguides named the “Mosquito method”, and demonstrated not only straight parallel waveguides but also horizontally and vertically curved designs with excellent optical characteristics. For higher density interconnection, multilayer waveguides are expected. The Mosquito method is capable of fabricating such a multilayer waveguide very easily. However, the core position accuracy is a concern because the liquid state monomer flows due to the needle scan for dispensing the cores.
In this paper, we successfully fabricate multilayer GI-circular core polymer parallel optical waveguides by optimizing the needle scan program, and realize a high core-position accuracy with a 125-m horizontal pitch. Then, we measure the optical characteristics of these waveguides and discuss the effect of core position error on the loss.

ポリマー光導波路を用いた広帯域・高密度オンボードインターコネクトの技術動向

ISHIGURE TAKAAKI

2015年度　第4回　フォトニックデバイス・応用技術研究会, 

2015.11

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Public lecture, seminar, tutorial, course, or other speech, 般財団法人光産業技術振興協会

Organic-Inorganic Hybrid Material, "SUNCONNECT®" for Optical Inter-connects

Hideyuki Nawata, Takehiro Nagasaw, Sayoko Tadokoro, Kei YasuiI, Daniel A. Sahade, Sho Yoshida, Yuki Saito, Kazuki Yasuhara, and Takaaki Ishigure

IEEE CPMT Symposium Japan (ICSJ2015) (Kyoto, Japan) , 

2015.11

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Oral presentation (general), IEEE CPMT Chapter

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In this paper, we report on the applications, as SM optical waveguides as well as lens arrays for optical connectors, of our organic-inorganic hybrid material, “SUNCONNECT®”. With respect to waveguide application, fabrication and optical property of GI (graded-index) optical waveguide and SI (step-index) optical waveguide was explained. In addition, lens array for optical coupling was fabricated by using conventional imprint mold.

Low-Loss Light Coupling Design for a Multimode Polymer Optical Waveguide via 45-degree Mirrors

Yoshie Morimoto and Takaaki Ishigure

IEEE CPMT Symposium Japan (ICSJ2015) (Kyoto, Japan) , 

2015.11

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Oral presentation (general), IEEE CPMT Chapter

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We theoretically analyze the optical loss in multimode waveguide based optical links including optical path conversion via a 45-degree mirror using a ray-trace simulator. We demonstrate a benefit of GI circular-core waveguides over the conventional SI square-core waveguide.

Interchannel Pitch Conversion (250 to 125 µm) in Multimode Polymer Optical Waveguide for High-Density Optical Wiring

Hikaru Masuda and Takaaki Ishigure

IEEE CPMT Symposium Japan (ICSJ2015) (Kyoto, Japan) , 

2015.11

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Oral presentation (general), IEEE CPMT Chapter

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We present a pitch conversion structure (250 - 125 μm pitch) in multimode polymer optical waveguides for high density interconnects, and investigate how to improve the coupling efficiency with a 12-ch. MMF ribbon.

Fabrication for Densely Aligned Multi-layer GI Circular Core Polymer Optical Waveguides

Kyuta Suzuki and Takaaki Ishigure

IEEE CPMT Symposium Japan (ICSJ2015) (Kyoto, Japan) , 

2015.11

, 

Oral presentation (general), IEEE CPMT Chapter

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We fabricate multilayer graded-index circular core multimode polymer parallel optical waveguides using the Mosquito method by optimizing the needle scan program, and realize a high core-position accuracy with a 125-μm vertical and horizontal pitch.

GI型円形コアマルチモードポリマーテーパ光導波路

Hoshihiko Toda and Takaaki Ishigure

電子情報通信学会光エレクトロニクス(OPE)研究会 (別府市，大分) , 

2015.10

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Oral presentation (general)

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Optical loss of waveguides caused at the connection points with other optical components and the accuracy of the alignment at the connection points are important issues to apply the waveguides for on-board interconnects. In this research, GI-circular-core polymer tapered waveguides are fabricated, in which a taper structure in which the core diameter gradually decreases along with the waveguide axis is formed. The GI circular core tapered polymer waveguides are fabricated using the Mosquito method. The GI cores are formed utilizing the diffusion between the core and cladding monomers. Polymer waveguides with a tapered structure maintaining a circular core cross-section is successfully fabricated. Meanwhile, we discuss the refractive index profile calculated from the diffusion equation: simulated and measured index profiles are compared.

モスキート法による高密度多段ポリマー光導波路の作製と低クロストーク化

Yusuke Kogo, Kyuta Suzuki, and Takaaki Ishigure

電子情報通信学会光エレクトロニクス(OPE)研究会 (別府市，大分) , 

2015.10

, 

Oral presentation (general)

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For the application to optical printed circuit boards, we developed the“Mosquito method,”as a fabrication technique for GI circular core polymer optical waveguides utilizing a microdispenser. However, multilayered waveguide using the Mosquito method has high crosstalk to the vertical neighbor cores. In this paper, we suppress this interchannel crosstalk for densely-aligned multilayered polymer optical waveguide.

Polymer waveguide for 3-D on-board optical circuits

ISHIGURE TAKAAKI

3rd Optical Interconnect in Data Centers Symposium (Cannes, France) , 

2015.09

, 

Oral presentation (invited, special)

円形断面を有するポリマーマイクロ流路作製

相賀 建人，石榑 崇明1

第76回　応用物理学会秋季学術講演会 (名古屋市，愛知) , 

2015.09

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Oral presentation (general), 公益社団法人　応用物理学会

45°ミラーによる低損失光結合のためのマルチモードポリマー光導波路の最適構造設計

森本 祥江，石榑 崇明

電子情報通信学会　2015ソサエティ大会 (東北大学，宮城) , 

2015.09

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Oral presentation (general), 電子情報通信学会

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High performance computing (HPC)のさらなる高性能化を見据え，光インターコネクト技術の導入が期待されており，マルチモードポリマー光導波路を用いた光配線板が検討されている．光配線板では，光源としてVCSEL(垂直面発光レーザ)を用いることが想定されているため，光源-導波路間・導波路-受光器間の結合部に，導波路端に形成した45°ミラーによる直角光路変換が必要とされる．この45°ミラーを介した光結合の際に生じる損失は，光配線板上の導波路ベース光リンクを構成する上で懸念事項となっている．本研究では，45°ミラーを形成した光導波路による，オンボード・ボード間光配線のリンクロスを，光線追跡シミュレーションにより計算し，低リンクロスを実現する光導波路の最適構造を議論する．