Optical Heterodyne Spectroscopy of Light Scattering by Laser Induced Phonons
| Project/Area Number |
63460062
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
物理計測・光学
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| Research Institution | Institute of Industrial Science, Univ. of Tokyo |
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Principal Investigator |
TAKAGI Kenshiro Inst.of Industrial Science Univ. of Tokyo, Professor, 生産技術研究所, 教授 (90013218)
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| Co-Investigator(Kenkyū-buntansha) |
CHOI P.-K. Dept.of Phys. Meiji Univ. Assistant, 理工学部, 助手 (30143530)
SAKAI Keiji Inst.of Industrial Science Univ. of Tokyo, Assistant, 生産技術研究所, 助手 (00215584)
TANAKA Hajime Inst.of Industrial Science Univ. of Tokyo Lecturer, 生産技術研究所, 講師 (60159019)
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| Project Period (FY) |
1988 – 1989
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| Project Status |
Completed (Fiscal Year 1989)
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| Budget Amount *help |
¥7,400,000 (Direct Cost: ¥7,400,000)
Fiscal Year 1989: ¥1,000,000 (Direct Cost: ¥1,000,000)
Fiscal Year 1988: ¥6,400,000 (Direct Cost: ¥6,400,000)
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| Keywords | Brillouin Scattering / Optical Beating Spectroscopy / Ultrasonic Spectroscopy / Ripplon / 光ヘテロダイン分光 |
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| Research Abstract |
The fundamental requirement in the ultrasonic spectroscopy is to observe the velocity and absorption over extensive frequency range. In the last few years, we have developed various experimental techniques, including planoconcave ultrasonic resonator and high resolution Bragg reflection (to be referred as HRB) method. The purpose of this research project is to establish a new technique which is useful for the measurement of phonon velocity and decay at hypersonic range. For this purpose, we took advantage of the light beating spectroscopy to detect the light scattering by the thermal phonons. The success of the HRB method has shown that the light beating is most effective to observe the very weak light of Brillouin scattering. In the investigation by this Grantin-Aid,we obtained various important results which are summarized as follows.
(a) We established the means to measure the phonon velocity and absorption in transparent solids at the frequency range up to 2GHz. The Gruneisen constant which represents the strength of phonon-phonon interaction, was estimated for sapphire from the results of hypersonic measurement. High frequency ultrasonic property was measured in GeO_2 glass. An absorption peak due to the structural relaxation was found around 600 MHz, which yields the distribution of the double well potential of oxygen atom in glass.
(b) A new optical beating technique was developed to observe Brillouin scattering by thermal fluctuation of liquid surface.The range of the measurement was extended up to 1MHz, which is one decade higher than the previous works. This technique will be a powerful means to investigate the dynamic property of liquid surface.
(c) We constracted several optical heterodyne systems to detect incoherent Brillouin scattering light by thermal phonons and obtained the characteristics and performance of each system through the preliminary test with them.
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Report
(3 results)
Research Products
(25 results)
