基于偏振双向反射分布函数的粗糙面光散射偏振特性研究

Analysis of Polarization Characteristics about Rough Surface Light Scattering Based on Polarized Bidirectional Reflectance Distribution Function

为了研究高斯粗糙面光散射偏振特性,基于微面元理论,建立偏振双向反射分布函数模型,推导出散射光的斯托克斯矢量。数值计算了椭圆偏振光和自然光经粗糙面散射后偏振特性随散射角变化情况,分析了入射角、方位角以及复折射率等因素对散射光偏振特性的影响。数值结果表明:椭圆度角和偏振度强烈依赖于入射角、方位角及复折射率,不同入射角和复折射率的椭圆度角曲线和偏振度曲线有相似的变化规律;不同方位角的椭圆度角曲线和偏振度曲线变化规律有较大区别,但方位角互补的两条偏振特性曲线关于散射角θr=0对称;椭圆度角在后向散射方向附近有极大值,偏振度在后向散射方向有极小值。

To study the polarization characteristics about Gaussian rough surface light scattering, the Stokes vector of scattering light is derived based on microfacet theory and polarized bidirectional reflectance distribution function. The polarization characteristics of rough surface scattering light are numerically calculated for both elliptically polarized light incidence and natural light incidence. The effects of incident angle, azimuth angle and complex refractive index on polarization characteristics of scattering light are studied. The result shows that the incident angle, the complex refractive index and the azimuth angle have a great influence on the ellipticity angle and the degree of polarization. The change trends of the degree of polarization curves and the ellipticity angle curves with different incident angles or complex refractive indexes have a high similarity. The change trends of the degree of polarization curves and the ellipticity angle curves with different azimuth angles have a large difference, but the two curves with complementary azimuth angles are symmetric about scattering angle θr = 0. The maximum value of the ellipticity angle is obtained around the backscattering direction, and the minimum value of the degree of polarization is obtained in the backscattering direction.