Details of a Researcher - Koike, Yasuhiro

Presentations -

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Recent Status of High-Speed Polymer Optical Fiber and Its Future Prospect

ISHIGURE TAKAAKI, KOIKE YASUHIRO

Laser and Quantum Electronics (日本) ,

2000.02

Oral presentation (invited, special), The Institute of electronics, Information and Communication Engineers

A lot of research interests are focused on the introduction of optical fiber even in the access network because of the growing demand for accessing Internet with high bit rate. Since inexpensive total system cost is strong]y required for LAN or access network, we have proposed a large-core, low-loss and high-bandwidth graded-index polymer optical fiber (GI POF) as a promising candidate of physical media. In this paper, we describe the recent development of the GI POF in its attenuation and bandwidth achieved by investigating a new polymer material and by theoretical analysis.

High-Performance Polymer Optical Fiber Lasers and Amplifiers

KURIKI KEN, KOBAYASHI TAKEYUKI, TAMURA TOSHIHIKO, TAGYA AKIHIRO, KOIKE YASUHIRO, OKAMOTO YOSHIYUKI

Photonics West, Optelectronics 2000, Technical Conference on Organic Photonics Materials and Devices II (Ssn Jose, USA) ,

2000.01

Oral presentation (invited, special), The International Society for Optical engineering (SPIE)

We report on the lasing action of the GI POF containing dyes, such as Rhodamine B, Rhodamine 6G, Perylene Orange, and Pyrromethene 567. These dyes have been incorporate into poly (methyl methacrylate-co-2-hydroxyethyl methacrylate). These fibers were transversely pumped at 532 nm with a frequency-doubled Q-switching ND: YAG laser. Slope efficiency of 24% and output of 1,3 mJ were obtained with a Rhodamine 6G-doped fiber. A Lifetime of 200,000 pluses at 10 Hz was achieved with a Rhodamine B-doped fiber.
GI POF containing a Nd-chelate have also been fabricated. The absorption spectrum of the fiber exhibited several strong bands in the visible and infrared region. We have observed infrared fluorescence (0.90, 1.60, and 1.3µm) of the Nd3+ ion of the fiber at room temperature when it was pumped with an Ar+ -pumped dye laser at 580 nm. The Judd-Often theory was applied to the absorption spectrum of Nd+ in polymer to determine the Judd-Ofelt parameters. From the theory, various radiative properties, such as transition probability, branching ratio, and emission cross section for various emission levels, have been determined and reported.

Rare Earth-Doped Graded Index Polymer Optical Fibers for Optical Amplification

TAKEYUKI KOBAYASHI, KURIKI KEN, NISHIHARA SUSUMU, KOIKE YASUHIRO, OKAMOTO YOSHIYUKI

Photonics West, Technical Conference, Rare-Earth-Doped Materials and Devices IV (California, USA) ,

2000.01

Oral presentation (invited, special), The International Society for Optical Engimeering (SPIE)

High-Bandwidth, Low-Loss Graded-Index Polymer Optical Fiber with Long term Reliability

ISHIGURE TAKAAKI, SATO MASATAKA, KOIKE YAUSHIRO

Workshop on Polymeric Materials for Microelectrics & Photonics Applications: Mechanics, Physics, Reliability, Processing, (POLY’99) (Paris, France) ,

1999.12

Oral presentation (invited, special), American Society of Mechanical Engineers (ASME International), The IEEE Components, Packing & Manufacturing Technology Society (IEEEE-CPMT)

プラスチック光ファイバーでインターネットを家庭へ

KOIKE YASUHIRO

第14回「大学と科学」公開シンポジウム「21世紀の新素材」－産業を活性化させる傾斜機能材料－ (Tokyo) ,

1999.12

Oral presentation (invited, special), 第14回「大学と科学」公開シンポジウム組織委員会

High-Speed Plastic Optical Fibers and Amplifiers

KOIKE YASUHIRO

International Symposium on Photonics and Applications (ISPA’99), Conference on Design,Fabrication,and Characterization of Photonic Devices (Singapore) ,

1999.12

Oral presentation (invited, special), The International Society for Optical Engineering (SPIE)

Recent status of the polymer optical fiber (POF) for high speed data communication and telecommunication is reviewed. The GI POF was proposed for the first time at Keio University, and several methodologies to fabricate GI POF have been currently proposed. In this paper, we clarify the great advantage of perfluorinated (PF) polymer as the polymer matrix of low-loss and high bandwidth GI POF. It is generally known that the PF polymer can decrease the intrinsic absorption loss compared with PMMA, which is the conventional material of POF. Furthermore, it was found that low material dispersion of the PF polymer is another advantage to obtain the high bandwidth GI POF.
It was clarified for the first time that the power distribution of modes formed by the mode dependence attenuation was the dominant factors of the higher bandwidth of the GI POF than theoretically predicted bandwidth, while the effect of the mode coupling was small.

Highly Scattering Optical Transmission Polymers for Liquid Crystal Display

TAGAYA AKIHIRO, KOIKE YASUHIRO

International Symposium on Photonics and Applications (ISPA’99), Conference on Design,Fabrication,and Characterization of Photonic Devices (Singapole) ,

1999.12

Oral presentation (invited, special), The International Society for Optical Engineering, (SPIE)

We proposed highly scattering optical transmission (HSOT) polymers and applied it to a light pipe of a backlighting system for liquid crystal displays (LCDs). The HSOT polymer backlighting system having not only approximately twice the brightness but also twice the efficiency of the conventional one was realized based on analysis of multiple scattering in the HSOT polymers. The problem of color dispersion which had been believed to be the nature of scattering phenomenon was solved by optimizing the heterogeneous structures in the HSOT polymers. As a result, the HSOT polymer backlighting system with sufficient color uniformity was achieved. In addition, the HSOT polymer backlighting system is suitable for recent thin LCDs because of these advantages.

ＰＯＦの動向

KOIKE YASUHIRO

ＮＴＴ－ＡＴ第４回エイトラムダフォーラム'99 (Tokyo) ,

1999.11

Oral presentation (invited, special)

Plastic Optical Fiber

KOIKE YASUHIRO

The 8th Asian Chemical Congress and Chemical Industry & Instrument Exhibition. (8ACC '99) (Taipei, Taiwan) ,

1999.11

Oral presentation (invited, special)

Research Strategy in Photonics Polymer

KOIKE YASUHIRO

7th SPSJ International PolymerConference (IPC 99) (Yokohama,Japan) ,

1999.10

Oral presentation (invited, special), The Society of polymer Science, Japan

Development of High-Speed, Low-Loss Polymer Optical Fiber and Optical Network

KOIKE YASUHIRO

Chitose International Forum on Photonic Scienses (Chitose, Japan) ,

1999.10

Oral presentation (invited, special)

POF for High-Speed Telecommunication

KOIKE YASUHIRO

International Conference on Advanced Fiber Materials (Ueda, Japan) ,

1999.10

Oral presentation (invited, special), The Society of Fiber Science and Technology, Japan, The Textile Mechinery Society of Japan, The Japan Research Association for Textile End-Use

Status of GIPOF System and Related Technologies

G.D. KHOE, KOIKE YASUHIRO, ISHIGURE TAKAAKI, P.K. BENNEKOM, H.P.A.V.D. BOOM, W. LI, G. YABRE

25th European Conference on Optical Communication (ECOC '99) (Nice France) ,

1999.09

Oral presentation (invited, special)

Highly Scattering Optical Transmission Polymer for Bright Display

TAGAYA AKIHIRO, KOIKE YASUHIRO

218th American Chemical Society National Meeting, (1999 Fall ACS Meeting), International Symposium on Polymers in Display Applications (New Orleans, USA) ,

1999.08

Oral presentation (invited, special), ACS

Recent Status of Polymer Optical Fiber for High-Speed Date Communication

KOIKE YASUHIRO, ISHIGURE TAKAAKI

SPIE Annual Meeting 1999, Conference on Organic Materials for Photonics Linear Optical Properties of Waveguides and fibers (Bellingham, USA) ,

1999.07

Oral presentation (invited, special), SPIE

Recent status of the polymer optical fiber (POF) for high speed communication and telecommunication is reviewed. The GI POF was proposed for the first time at Keio University, and several methodologies to fabricate GI POF have been currently proposed. In this paper, we clarify the great advantage of perfluorinated (PF) polymer which can decrease the intrinsic absorption loss compared with poly methyl methacrylate (PMMA), which is the conventional material of POF. Furthermore, it was found that low material dispersion of the PF polymer is another advantage to obtain the high bandwidth GI POF. It was clarified for the first time that the power distribution of modes formed by the mode dependent attenuation was the dominant factor of the higher bandwidth of the GI POF than theoretically predicted bandwidth, while the effect of the mode coupling was small.

伝送技術－プラスチック光ファイバーの展望

KOIKE YASUHIRO

有機エレクトロニクス材料研究会第104回研究会 (長野) ,

1999.06

Oral presentation (invited, special), 有機エレクトロニクス材料研究会新世代技術研究会機能性高分子材料研究会財団法人　浅間テクノポリス開発機構

photonics Polymer for Multimedia

KOIKE YASUHIRO, TAGAYA AKIHIRO, ISHIGURE TAKAAKI

プラスチック成形加工学会第10回プラスチック成形加工学会年次大会 (Tokyo) ,

1999.06

Oral presentation (invited, special), プラスチック成形加工学会

Novel Photonics Polymers in High-Speed Telecommunication

KOIKE YASUKIRO

5th International Conference on Frontiers of Polymers and Advanced Materials,Conference&Exhibit. (Pozan,Poland) ,

1999.06

Oral presentation (invited, special)

High-Power Polymer Optical Fiber Lasers and Amplifiers

KOBAYASHI TAKEYUKI, KURIKI KEN, IMAI NANA, TAMURA TOSHIHIKO, SASAKI KEISKUKE, KOIKE YASUHIRO, OKAMOTO YOSHIYUKI

Photonics West, Optoelectronics ’99, Symposium on Organic Photonic Device (California, USA) ,

1999.01

Oral presentation (invited, special), The Society for Optical Engineering, (SPIE)

We demonstrate efficient and photostable laser action in graded index polymer fiber laser with organic dyes such as Rhodamine, Perylene and Pyrromethenes. Slope efficiency of 47% and output of 2.6 mJ have been obtained with a Rhodamine 6G-doped fiber laser. Moreover, we encapsulated rare ions to incorporate them into polymer matrices and studies spectroscopic properties of europium chelates in polymer hosts. Superfluorescent polymera fiber source based on Eu chlate-doped polymer optical fiber was demonstrated.

屈折率分布型ポリマー光ファイバーの現状と展望

KOIKE YASUHIRO, NIHEI EISUKE, ISHIGURE TAKAAKI

98-2高分子エレクトロニクス研究会光を透す高分子とエレクトロニクス (Tokyo) ,

1999.01

Oral presentation (invited, special), 社団法人　高分子学会　高分子エレクトロニクス研究会

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