Polarized bidirectional reflectance distribution function for film upon rough substrate

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 Brewsters angle decreases with the increase of incident angle.