2006 Fiscal Year Final Research Report Summary
Correlations in optical fluctuations in multiple scattering medium and its applications
| Project/Area Number |
16340117
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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 | 一般 |
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| Research Field |
原子・分子・量子エレクトロニクス・プラズマ
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| Research Institution | Shizuoka University |
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Principal Investigator |
TOMITA Makoto Shizuoka University, Graduate school of science and technology, Professor, 創造科学技術大学院, 教授 (70197929)
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| Project Period (FY) |
2004 – 2006
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| Keywords | multiple scattering / speckle / hole burning / fluctuations / correlations |
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| Research Abstract |
We investigated correlations in optical fluctuations in multiple scattering medium and developed its applications in photonics.
[1] Coherence coupling effect in a multiple scattering medium
Coherence coupling effect in a space and time resolved nonlinear correlation measurement in a multiple scattering medium was investigated. In this measurement two laser beams are injected onto the medium and the total intensity of nonlinear optical signal is measured as a function of the relative time delay and the relative spatial separation distance, between two laser beams. We examined the form factor of the coherence coupling effect as a function of the frequency and the wave vector differences between two laser beams. The form factor shows an interesting feature which is characteristic to the speckle fluctuations inside the multiple scattering medium, that is, the form factor does not scale with the transport mean free path but it scales with the sample thickness even in the refection geometry.
[2] Persistent hole burning in multiple scattering media
Time development of a persistent hole burning in photo-reactive and multiple scattering media was investigated. In this hole burning, a writing laser beam recodes volume speckle pattern inside the medium through the photo-reactive process, then, the luminescence intensity excited by a reading beam is measured as a function of the frequency or the wave vector difference between the writing and the reading beams. The time development reflects the statistics of the intensity fluctuations in the speckle inside the medium. One of the striking results is that the maximum hole depth is 〜0.26. The dependence of the hole shape and width on the sample thickness, transport mean free path and absorption length were measured and experimental results show good agreement with a previously reported theoretical calculation on the basis of a diffusion approximation.
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