粗糙基底上涂层的极化双向反射分布函数

Polarized bidirectional reflectance distribution function for film upon rough substrate

为了有效检测光学基底和镀膜后的光学元件质量,根据微面元电磁散射理论建立了一阶极化光散射模型,推导求解出其极化双向反射分布函数,获得了极化双向反射分布函数PP项与散射角和方位角的三维关系。数值模拟分析了入射角、基底粗糙度及不同涂层厚度对极化双向反射分布函数的影响。数值结果表明:极化双向反射分布函数与入射角、相关长度、均方根高度及涂层厚度均成反比。P极化入射产生的P极化双向反射分布函数强烈依赖于入射角、散射角和方位角。布鲁斯特角的位置随着入射角的增加逐渐向散射方位角小的方向移动。

In order to detect the quality of the substrate and coated optical elements effectively,the first-order vector perturbation microfacet polarized light scattering model was established by microfacet theory and the polarized bidirectional reflectance distribution function was derived.The influence of incident angle,degree of roughness about substrate and the thickness of film to the polarized bidirectional reflectance distribution function was simulated and analyzed numerically.And the relationships among PBRDFPP,scattering angle and azimuth angle were talked about.The results show that the polarized bidirectional reflectance distribution function is inversed to incident angle,correlation length,root-mean-square height,and the thickness of film.PBRDFPP depends on incident angle,scattering angle and azimuth angle strongly.The position of Brewster′s angle decreases with the increase of incident angle.