2002 Fiscal Year Final Research Report Summary
Generation of fractal optical waves by means of light scattering and analysis of their statistical properties
| Project/Area Number |
13650043
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Applied optics/Quantum optical engineering
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| Research Institution | HOKKAI-GAKUEN UNIVERSITY |
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Principal Investigator |
UOZUMI Jun Hokkai-Gakuen University, Faculty of Engineering, Professor, 工学部, 教授 (50184982)
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| Project Period (FY) |
2001 – 2002
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| Keywords | Light scattering / Fractal speckle / Power law / Speckle phase / Clipping statistics / Nondiffracting speckle / Self-affin fractal / Fractal dimension |
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| Research Abstract |
Recently, it was shown by the head investigator's group that random optical fields with fractal intensity distributions can be generated in the Fraunhofer region of a plane diffuser. The present study aims at extending this research by developing methods for generating such fields in areas other than the Fraunhofer region, and by analyzing statistical properties of such fields.
1. Properties of fractal speckles produced in various regions
Assuming that a diffuser is illuminated by coherent light with the intensity distribution following a power function with the exponent -D, computer simulations were conducted for 0 < D < 3, and revealed that the intensity correlation function shows non-power-law behaviors for 2 【less than or equal】 D < 3, agreeing with the theoretical predictions, and that power-law intensity correlations appear for 0 < D 【less than or equal】 1 as is in the case of 1 < D < 2.
It was also shown theoretically and experimentally that fractal speckles can be generated in the Fresnel region and image plane as well as in the Fraunhofer region of the diffuser.
2. Statistics of the clipped intensity and the phase
Clipped intensity of fractal speckles was investigated by computer simulations and some fundamental knowledge for estimating the original fractality from the clipped intensity was obtained. Phase statistics of fractal speckles was also investigated, and was shown to have fractality.
3. Generation of nondiffracting fractal beams
It was shown that nondiffracting fractal beams can be generated by employing modified optical configurations for nondiffracting beams.
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