Analyses and applications of singular intensity variations in Gaussian scattering fields of laser light

激光高斯散射场奇异强度变化分析及应用

基本信息

批准号：
09650038
负责人：
UOZUMI Jun
金额：
$ 2.18万
依托单位：
HOKKAIDO UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1997
资助国家：
日本
起止时间：
1997 至 1998
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-09650038/
关键词：
Light scattering Gaussian speckle Clustered speckle Long correlation tail Fractal speckle Doubly scattered speckle Power-law illumination Power-law intensity correlation 強度相関べき則円環状照明

项目摘要

Recently, random fields with singular properties were found in the framework of Gaussian speckles. The present study aims at analyzing statistical properties and generation conditions of such random fields through theoretical, experimental and simulation approaches.1. Generating mechanism of structured specklesStructured speckles (clustered speckles) are found to appear when a diffuser is illuminated by a thin ring-slit aperture. An isotropy of the speckle clustering was shown to be due to circular symmetry of the ring slit. An origin of speckle clustering was shown by means of computer simulations. Developing process of partially-developed clustered speckles are revealed experimentally by using small-roughness diffusers.2. Axially long spatial correlationWith relation to properties of a non-diffracting beam, it was shown theoretically that the clustered speckles produced by the ring-slit illumination have very long spatial correlations in the axial direction. The results were verified by experiments.3. Generation of fractal specklesIt was shown experimentally that a double scattering process using a random fractal diffuser and an ordinary diffuser can produce speckle intensity distributions with a fractal property in a Fourier transform plane of the second diffuser. This verified a theoretical prediction given previously. A 3D correlation properties of the speckles were also examined.4. Fractal speckles in Fresnel and image regionsIt was shown that speckle intensity distributions with fractal properties can also be generated in the Fresnel diffraction regions and in the image plane of the ordinary diffuser by using suitable configurations.

最近，在高斯斑点的框架中发现了具有单数特性的随机字段。本研究旨在通过理论，实验和仿真方法分析此类随机场的统计特性和产生条件。1。当扩散器被细的环形缝隙光圈照亮时，发现出现结构化斑点斑点（簇状斑点）的生成机制（簇状斑点）。斑点聚类的各向同性被证明是由于环狭缝的圆形对称性引起的。通过计算机模拟显示了斑点聚类的起源。通过使用小型延伸器扩散器2。与非分裂光束的性质有关的轴向长的空间相关性，从理论上讲，环插条照明产生的聚类斑点在轴向方向上具有很长的空间相关性。通过实验验证了结果3。通过实验表明，分形斑点的产生表明，使用随机分形扩散器和普通扩散器的双散射过程可以在第二扩散器的傅立叶变换平面中产生带有分形特性的斑点强度分布。这验证了先前给出的理论预测。还检查了斑点的3D相关属性。4。表明菲涅耳和图像区域中的分形斑点显示，也可以在菲涅耳衍射区和普通扩散器的图像平面中生成具有分形特性的斑点强度分布，并使用合适的配置在普通扩散器的图像平面中生成。