An experimental study of very rough surfaces interacting with light

Abstract

A systematic analysis of the spatial distribution of radiation scattered from surfaces having roughness heights large compared with wavelength shows that a shadowing function always limits the efficacy of reflection on the microfacet model of a ground glass. The facet slope distribution already demonstrated by an immersion technique is found again and shown to be related to the RMS surface roughness. This approach that supports the validity of a first order theory of microreflections is completed by an investigation on multiple reflections as revealed by the depolarized radiation. The depolarization ratio that can be high enough, when a large dissymmetry exists between incident and scattered rays, essentially depends on the slope distribution width. It does not appear that peak or ridge effects significantly alter phenomena resulting from a simple theory.