Stokes parameters polarization scattering properties of optical elements surface of different material

The micro-morphology and refractive index of the optical element surface not only affect the quality of the transmitted beam in the optical system, but also cause the polarization modulation of the beam. To characterize the effect of surface properties of optical elements on polarization modulation characteristics, an improved polarization bidirectional reflectance distribution function (pBRDF) is obtained based on the theory of Micro-facet scattering, then a Stokes parametric polarization scattering mathematical model between the object surface and the modulated beam is established. The effect regulations of incident angle, surface roughness, scattering angle and scattering azimuth on the scattering distribution of Stokes parameters are analyzed by numerical simulation. The modified J.A. Woollam ellipsometry is used to measure and analyze Stokes parameters of samples with different materials and roughness. the distribution relationships between scattering angle and degree of linear polarization and polarization angle are obtained. Comparing with results of simulation and experiment, and it coincide well. It provides technical and theoretical support for the subsequent surface quality assessment and defect detection testing based on scattering.