部分空间相干光经准均匀介质的散射

Scattering of spatially partially coherent light on quasi-homogeneous medium

  • 摘要: 基于一阶波恩近似,研究了部分空间相干平面光经准均匀介质的散射特性,得到了远场散射光谱强度和光谱相干度的解析表达式。讨论了入射光的空间相干性和介质特性对散射场光谱强度和光谱相干度的影响。比较了入射光是完全相干光和部分相干光时,散射场光谱强度和相干度的区别。研究结果表明:入射光的空间相干性对散射场光谱强度的分布有重要影响;随着入射光空间相干长度的增大,光谱宽度减小;光谱相干度随着入射光束腰宽度或介质有效半径的增大而减小。当准均匀介质的有效半径和相干长度、入射光的空间相干长度满足一定条件时,散射光是完全相干光。

     

    Abstract: Based on the accuracy of the first-order Born approximation, the scattering properties of a spatially partially coherent plane-wave light incident on a quasi-homogeneous random medium were investigated. The analytical expressions for the spectral density and the spectral degree of coherence of the scattered field in the far zone were derived. The influence of the spatial coherence of the incident field and the properties of the scattering on the spectral density and the spectral degree of coherence of the scattered field was examined. Compared with a fully coherent light, the spectral density and the spectral degree of coherence of the field generated by scattering of a partially coherent light were analyzed. The results indicate that the spatial coherence of the incident light has an important role in the behavior of the spectral density of scattered field. With an increase of the correlation length of the GSM beam, the effective angular width of the spectral density of the scattered field decreases. The spectral degree of coherence of the scattered field increases with decreasing beam width of the incident light or effective radius of the medium. The scattered field is fully coherent when the appropriate choices of the effective radius and the correlation length of the medium, the spatial correlation length of the incident light are made.

     

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