| Project/Area Number |
05555253
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| Research Category |
Grant-in-Aid for Developmental Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
高分子構造・物性(含繊維)
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| Research Institution | TOKYO UNIVERSITY OF AGRICULTURE AND TECHNOLOGY |
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Principal Investigator |
MIYATA Seizo Tokyo University of Agriculture and Technology Faculty of Technology, Professor, 工学部, 教授 (90015066)
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| Co-Investigator(Kenkyū-buntansha) |
HAYASHI Akio Nippon Oil and Fats, Tsukuba Laboratory, Researcher, 筑波研究所, 研究員
GOTO Yoshitaka Nippon Oil and Fats, Tsukuba Laboratory, Senior researcher, 筑波研究所, 主任研究員
WATANABE Toshiyuki Tokyo University of Agriculture and Technology Faculty of Technology, Research A, 工学部, 助手 (10210923)
臼井 博明 東京農工大学, 工学部, 助教授 (60176667)
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| Project Period (FY) |
1993 – 1994
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| Project Status |
Completed (Fiscal Year 1994)
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| Budget Amount *help |
¥14,000,000 (Direct Cost: ¥14,000,000)
Fiscal Year 1994: ¥3,500,000 (Direct Cost: ¥3,500,000)
Fiscal Year 1993: ¥10,500,000 (Direct Cost: ¥10,500,000)
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| Keywords | Nonlinear optics / Domain inversion / Frequency conversion / Second harmonic generation / Periodical structure / Waveguide / Phase-matching / Langmuir-Blodgett film / 非線形光学 / 高分子 |
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| Research Abstract |
Recently organic nonlinear optical (NLO) materials have been extensively investigated because of their large second-order nonlinear optical coefficients and ultra fast response in the field of optoelectronics. A conversion efficiency of frequency doubler is proportional to the optical density of fundamental beam. The waveguide geometry has advantages for nonlinear optical (NLO) applications, because of the high power density that can be achieved over a long propagation length and utilization of diagonal tensor components. In order to obtain a highly efficient second harmonic generation (SHG), the materials match the phase velocity over the long propagation distance for light at fundamental and harmonic waves. By carefully adjusting the waveguide thickness the dispersion of the medium allows different mode at the two wavelengths to have the same effective refractive index n_<eff>, which is called as modal dispersion phase-matching (PM). The effective refractive index of waveguide critically depends on the waveguide dimensions. Therefore fabrication tolerance of waveguide dimension to fulfilll phase-matching condition is limited to less than a few nm. Furthermore optical-field overlap must be large between the propagating waveguide modes to improve a conversion efficiency. In general, it is difficult to obtain large dimension tolerance, together with high overlap integral for modal dispersion phase-matching. Here we report that five-layr organic waveguides prepared by Langmuir-Blodgett techniques exhibit high overlap integral as well as large fabrication tolerance of thickness up to 56 nm. This large fabrication tolerance for phase-matching is 8.6 times larger than that of conventional three layr waveguide.
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