涂层表面反射偏振建模及其特性分析方法

Modeling and Characteristic Analysis Methods for Reflection Polarization on Coated Surfaces

为了研究涂层表面光反射偏振特性,提出了一种基于蒙特卡罗方法的偏振双向反射分布函数(PBRDF)建模方法。该方法先利用傅里叶变换完成对涂层基底双层粗糙表面的三维重构,再根据微面元理论和菲涅耳方程求解单个面元上反射与折射的随机过程,最后应用偏振光线跟踪技术和蒙特卡罗方法对重构表面的偏振光散射过程进行统计求和,从而得到涂层表面的PBRDF。实验结果表明,所提方法建立的PBRDF正确,且相比于现有模型具有更高的精度。最后分析了入射角、表面粗糙度、基底材质及涂层光学厚度对涂层表面光反射偏振特性的影响规律,以为其表面的探测和测量提供理论依据。

To study the polarization characteristics of light reflection from coated surfaces,this paper proposed a modeling method based on the Monte Carlo method for the polarized bidirectional reflectance distribution function(PBRDF).Specifically,Fourier transform was performed for the threedimensional reconstruction of a coatingsubstrate doublelayer rough surface.Then,the microfacet theory and the Fresnel equation were employed to solve the processes of stochastic reflection and refraction from a single facet,and the process of polarized light scattering on the reconstructed surface was statistically summated by the polarization ray tracing technique and the Monte Carlo method to obtain the PBRDF of the coated surface.Experimental results show that the PBRDF built by the proposed method is correct and the proposed model outperforms the existing models in accuracy.Finally,the effects of the incident angle,surface roughness,substrate material,and optical thickness of the coating on the polarization characteristics of light reflection from the coated surface are analyzed to provide a theoretical basis for the detection and measurement of coated surfaces.