| Project/Area Number |
63550254
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
電子通信系統工学
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| Research Institution | Toyohashi University of Technology |
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Principal Investigator |
MIYAZAKI Yasumitsu Toyohashi University of Technology. Department of Information and Computer Sciences, Professor, 工学部, 教授 (00023169)
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| Co-Investigator(Kenkyū-buntansha) |
YAMAGA Mitsuo Gifu University, Department of General Education, Associate Professor, 教養部, 助教授 (90159202)
GOTO Nobuo Toyohashi University of Technology, Department of Information and Computer Scien, 工学部, 講師 (60170461)
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| Project Period (FY) |
1988 – 1990
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| Project Status |
Completed (Fiscal Year 1990)
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| Budget Amount *help |
¥2,300,000 (Direct Cost: ¥2,300,000)
Fiscal Year 1990: ¥200,000 (Direct Cost: ¥200,000)
Fiscal Year 1989: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 1988: ¥1,600,000 (Direct Cost: ¥1,600,000)
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| Keywords | Optical amplifier / Optical integrated circuits / Garnet thin film / Optical waveguide / ガーネット薄膜 |
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| Research Abstract |
Optical thin film amplifiers can be a basic element in integrated optic circuits for optical communication and signal processing.
The thin film of 1.3 at. % Nd doped yttrium gallium garnet( Nd : YGG) were deposited on substrates of yttrium aluminium garnet (YAG) by RF sputtering. The amorphous films deposited at 600^ﾟC were crystallized by annealing at 1000^ﾟC. The minimum optical propagation loss (at 1064nm ) was 2.2dB/cm.
The absorption spectrum and the fluorescence spectrum of Nd : YGG were minutely measured. The peak of the absorption spectrum was located at 808nm. The peaks of the fluorescence spectrum were located at 1057.5nm, 1060.0nm and 1061.87nm.
To obtain a signal light of 1.06mum band, a tunable Nd : YAG laser pumped by LD was prepared. A thin etaron of thickness of 0.14mm was put in a cavity as the device to choose wavelength for 1064nm and 1061.5nm. A maximum output power of about 0.5mW and 2mW were obtained for 1061.5nm and 1064nm, respectively.
The gain and the S/N characteristics measured by using signal at wavelength 1061.5nm. As the results, the gain saturation was confirmed by increasing the signal power. Approximately, linear gain characteristics were obtained for the signal power of 10muW. The maximum gain of 3.7dB was obtained for pumping of about 13mW and the S/N ratio was 5.4dB.
The amplification characteristics of TW type amplifier for steady state were analyzed by rate equations for a fourーlevel system. From the numerical analysis, the gain of about 10dB is obtained for the signal power of 10muW with the pumping of lmW, the amplifier length of lcm and the film thickness of 2.5mum.
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