Numerical simulation of monochromatic light scattering on stratified surfaces

Abstract

The integral polygaussian model of random processes is employed for simulation of stratified roughness formed by secondary abrasive finishing treatment or wear of an initially rough normal surface. Examples of simulated profiles and dependencies of surface non-gaussian statistical parameters on the type and stage of the treatment are presented. Numerical analysis of scattering of a monochromatic gaussian beam based on the thin phase screen approximation demonstrates that non-gaussian features of the surface lead the strong specular peak due to the scattering from the upper smooth surface strata manifesting at the very beginning of the treatment and dominating over the diffuse scattering during all the process of the surface modification. The diffuse scattering radiation for stratified surfaces is strongly concentrated in the near- specular direction. The results of the investigation shows that traditional methods of normal surface roughness estimation based on the magnitude of the specular component of the scattering and the form of the diffuse indicatrice may result in misinterpretation when applied to the stratified surface.