| Project/Area Number |
11555017
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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 |
Applied optics/Quantum optical engineering
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| Research Institution | Osaka Prefecture University |
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Principal Investigator |
WADA Kenji Osaka Prefecture University, Dept.Physics and Electronics, Research Associate, 工学研究科, 助手 (40240543)
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| Co-Investigator(Kenkyū-buntansha) |
CHO Yoshio Oyokoden, Co.Ltd., R&D Coordinator, 技術開発顧問(研究職)
HORINAKA Hiromichi Osaka Prefecture University, Dept.Physics and Electronics, Professor, 大学院・工学研究科, 教授 (60137239)
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| Project Period (FY) |
1999 – 2000
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| Project Status |
Completed (Fiscal Year 2000)
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| Budget Amount *help |
¥13,300,000 (Direct Cost: ¥13,300,000)
Fiscal Year 2000: ¥4,900,000 (Direct Cost: ¥4,900,000)
Fiscal Year 1999: ¥8,400,000 (Direct Cost: ¥8,400,000)
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| Keywords | two photon absorption / ultrafast optical pulse / GaN / autocorrelator / 自己相関測定 |
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| Research Abstract |
A compact ultrafast optical pulse autocorrelator contained a two-photon semiconductor photodetector was fabricated aiming at an estimation of pico- or femto-seconds optical pulse duration. We started with making examination of two-photon absorption properties of commercially available semiconductor elements (light-emitting diodes or photodiodes). As a result, it was found that all of InGaN, AlGaAs light emitting diodes and GaAsP, GaP photodiodes prepared for the experiment had a good sensitivity as two-photon photodetectors. In the next year, a novel structure of autocorrelator was proposed and tested for picosecond optical pulse measurements. An interferometer inside the auocorrelator consists of close placed two pieces of silica glass ; one is fixed and the other is rotated. The pulse beam component passing through the rotating silica glass is yielded a relative time delay corresponding to the variation of path-length due to the rotation. Then both of pulse beam components passing through the glasses overlap each other only by focusing them on a photodetector with a condensing lens. The intensity autocorrelation trace was thus obtained in real time, without great difficulty in alignment, by sensing the two-photon signal from the above photodetector as a function of the time delay. In addition, a phase fringe-resolved autocorrelation trace was also obtained by utilizing a diffraction of the pulse beam at the boundary of the glasses. We confirmed experimentally that this autocorrelation traces could be monitored, at least, in a wide range from 740 nm to 840 nm and at input pulse average power as low as 100 mW, respectively. We also treated these autocorrelation measurements numerically using Fraunhofer-diffraction formula, taking into account the influence of the dispersion of silica glasses. As a result, we estimated that the proposed autocorrelator was available to measure ultrafast optical pulse as short as tens of femtoseconds.
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