| 研究課題/領域番号 |
21K03603
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| 研究種目 |
基盤研究(C)
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| 配分区分 | 基金 |
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| 応募区分 | 一般 |
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| 審査区分 |
小区分15020:素粒子、原子核、宇宙線および宇宙物理に関連する実験
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| 研究機関 | 立教大学 |
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研究代表者 |
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| 研究期間 (年度) |
2021-04-01 – 2023-03-31
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| 研究課題ステータス |
中途終了 (2022年度)
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| 配分額 *注記 |
4,160千円 (直接経費: 3,200千円、間接経費: 960千円)
2023年度: 520千円 (直接経費: 400千円、間接経費: 120千円)
2022年度: 1,820千円 (直接経費: 1,400千円、間接経費: 420千円)
2021年度: 1,820千円 (直接経費: 1,400千円、間接経費: 420千円)
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| キーワード | polarization stability / noise / coherence / Interferometer / Mach-Zehnder / Laser / Gravity |
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| 研究開始時の研究の概要 |
Gravity is one of the four universal forces, but we do not understand it as much as the other three, particularly at microscopic scales. Attempts to measure gravity at very close distances were concentrated up to now only on mechanical approaches which suffer from external influences like electrostatics. Here, I propose a new method by using relativistic effects on laser-light for the measurements which would reduce these influences drastically. As these effects are very small, my research is concentrated on improving the methods for measuring phase distortions due to gravity in laser-light.
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| 研究実績の概要 |
I succeeded to build a laser Doppler-interferometer, connected to a high-speed sampling oscilloscope, with which oscillation-amplitudes at 1~5kHz below picometer-ranges (<10^-12 m) could be measured. The first attempt of building such an instrument lagged clearly in polarization stability as the measured ground noise could not be lowered below 1pm/Hz^(1/2) even with a maximum sampling rate of 5MHz. The last measured ground noise is now at 0.13pm/Hz^(1/2).
The instrument has experienced upgrades regarding the polarization stability in the form of Glan-Taylor prisms which are now in front of the waveplates on the recombining beam-splitter side and a Faraday isolator at the laser-input. Furthermore, care has been taken to ensure an equal optical path length for both the reference and the signal beam path by using polarization maintaining fibers. This increased the coherence of both beams and thus also the contrast of the observed fringes at the detectors.
One minor aspect of the conducted research was to ensure the usability of the Piezo-test chip even for oszillation amplitudes below a picometer. This is important to keep the dynamic constrast low and thus the resolution of the measurements high. The results clearly proof the capability of the test-chip.
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