1993 Fiscal Year Final Research Report Summary
High-speed superconducting optical modulator prepared by oxide heteroepitaxy
| Project/Area Number |
04555070
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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 |
電子材料工学
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| Research Institution | Osaka University |
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Principal Investigator |
KOBAYASHI Takeshi Osaka Univ., Dept.of Eng.Science, Professor, 基礎工学部, 教授 (80153617)
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| Co-Investigator(Kenkyū-buntansha) |
HASHIGUCHI Shoichi Sumitomo cement Co., Ltd., Researcher, 中央研究所, 研究員
FUJII Tatsuhiko Osaka Univ., Dept.of Eng.Science, Research Associate, 基礎工学部, 助手 (40238530)
SAKUTA Ken Osaka Univ., Dept.of Eng.Science, Instructor, 基礎工学部, 講師 (70221273)
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| Project Period (FY) |
1992 – 1993
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| Keywords | Electrooptic material / Optical modulator / Epitaxy |
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| Research Abstract |
In this work, we fabricated the high speed optical modulator, used an oxide superconducting material. The key technology of this device is making the high quality superconducting thin film that exhibits as the transmission line, on an electrooptic substrate.
We found that YSZ is a good material for the buffer layr between the Y-cut LiNbO_3 that is electrooptic material, and YBa_2Cu_3O_y (YBCO) that is superconducting transmission line. In this combination of materials, each layr of the YSZ and the YBCO grows epitaxially. This is the first report of the epitaxial growth of the superconducting film on the electrooptic substrate. This technic makes us the divice that made from the all epitaxially grown films.
We fabricate the Mach-Zehnder phase-modulation type optical modulator used this heteroepitaxial multulayr structure. We actually tested the modulator of both a transmission property up to 200GHz and an optical modulation property by pulse signal.
This work, on the other hand, made a new technic concerning the laser deposition method. The laser deposited films have so-called droplets on the films, that make the film quality degraded. The "eclipse" method skillfully breaks this problem, and let us obtain the droplet-free oxide films. The YBCO epitaxial films by means of the eclipse method show the critical temperature of 93K.
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