| Project/Area Number |
12555070
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 展開研究 |
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| Research Field |
Intelligent mechanics/Mechanical systems
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| Research Institution | The University of Tokyo |
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Principal Investigator |
FUJITA Hiroyuki Institute of Industrial Science, Univ. Tokyo, Professor, 生産技術研究所, 教授 (90134642)
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| Co-Investigator(Kenkyū-buntansha) |
ATAKA Manabu Institute of Industrial Science, Univ. Tokyo, Research Associate, 生産技術研究所, 助手 (80302628)
TOSHIYOSHI Hiroshi Institute of Industrial Science, Univ. Tokyo, Lecturer, 生産技術研究所, 講師 (50282603)
KOBAYASHI Dai Tokyo Denki University, Lecturer, 工学部, 講師 (30312036)
SAWADA Renshi NTT, Communication Energy Lab., Principal Researcher, ネットワークインテグレーション研究部・光マイクロマシン研究グループ, 主幹研究員
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| Project Period (FY) |
2000 – 2001
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| Project Status |
Completed (Fiscal Year 2001)
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| Budget Amount *help |
¥13,700,000 (Direct Cost: ¥13,700,000)
Fiscal Year 2001: ¥3,000,000 (Direct Cost: ¥3,000,000)
Fiscal Year 2000: ¥10,700,000 (Direct Cost: ¥10,700,000)
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| Keywords | Optical communication / micromachine / optical matrix switch / Anisotropic etching / micro actuator |
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| Research Abstract |
The purpose of this research is to fabricate an N x N optical matrix switch by micromachining technologies for WDM (wave division multiplex) optical communication networks. The switch consists of N x N movable mirrors on a chip and 2N V-grooves for optical fiber alignment. The optical beams from N input fibers are reflected by N mirrors at appropriate positions to connect light beams to N output fibers. We have obtained the following results :
(1) Pre-aligned micromirrors and V-grooves by micromachining
Thin micromirrors that are vertical to the substrate and V-grooves that have exact 45 degree angles were fabricated simultaneously by wet anisotropic etching of single crystal silicon. Easy pig-tailing was possible by inserting fibers in V-grooves. The insertion loss was less than 1 dB because of precise alignment determined by crystal graphic orientation. Higher packing density of micromirrors was achieved by combining dry anisotropic etching and wet anisotropic etching subsequently. The coupling loss decreased because the distance between input and output ports became shorter.
(2) Self-latching electromagnetic actuation and arrayed actuator
A permalloy piece attached to the moving mirror was pulled by a combined electro/permanent magnet. The permanent magnet enabled the self-latching operation of the mirror. Because energy dissipation occurs only at the switching from one state to another, we could minimize the energy consumption. Arrayed coils that match the arrayed mirrors were fabricated. The planar coil was 500-800 micrometers in diameter and 20-50 micrometers in thickness. We could generate enough magnetic field for actuation with 2 A pulse current in the coil.
(3) Optical evaluation
A 2 x 2 elementary switch was fabricated and tested. It had insertion loss of 0.8 dB with single mode fibers, switching speed of 2 ms, contrast of 50 dB and lifetime of more than 20 million operations.
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