偏振光在浑浊介质中传输的偏振特性的研究对实现各类偏振光技术具有重要意义。建立一种非球形粒子介质模型,并采用T矩阵法和矢量蒙特卡罗模拟相结合的方法,计算分析含不同非球形粒子的介质中的偏振光经过多次散射形成的后向散射光的偏振特性。按照介质所含非球形粒子的尺寸分为瑞利散射粒子介质和米氏散射粒子介质。结果表明:瑞利散射粒子介质中,不同粒子形态对线偏振光和圆偏振光的后向散射光的偏振特性的影响不显著,线偏振光保偏能力优于圆偏振光,线偏振方向得到保持,而圆偏振光旋性发生改变;米氏散射粒子介质中,不同粒子形态对后向散射光的偏振特性有显著影响,光学厚度大时,各介质中的圆偏振光保偏能力优于线偏振光,厚度小时线偏振光的保偏能力优于圆偏振光。此外,粒子的形态对偏振光后向散射光偏振度空间分布及光强空间分布均有显著影响。

The polarization characteristics of the polarized light propagating in a turbid medium are of considerable importance in various polarization-related technologies. Here, a light propagation model is established for a turbid medium comprising randomly oriented non-spherical particles. Further, the polarization characteristics of the backscattering light after multiple scattering are numerically evaluated for a turbid medium comprising different non-spherical particles based on the T-matrix method and the vector Monte Carlo simulations. During this process, the medium is categorized as a Rayleigh-scattering-particle medium or a Mie-scattering-particle medium based on the non-spherical particle size in the medium. The results show that in the Rayleigh-scattering-particle medium, the influence of particle shape on the polarization characteristics of the backscattering light of the linearly-polarized light and circularly-polarized light is considerably small, the polarization preservation ability of the linearly-polarized light is better than that of the circularly-polarized light, and the linearly-polarized direction is maintained, whereas the circularly-polarized rotation is reversed. Conversely, in the Mie-scattering-particle medium, the different particle shapes considerably affect the polarization characteristics of the backscattering light; the polarization preservation ability of the circularly-polarized light is better than that of the linearly-polarized light at large optical thicknesses, and the opposite is true at small optical thicknesses. Furthermore, the particle shapes significantly influence the spatial distribution of the polarization degree and backscattering intensity of the polarized light.