Abstract

It is well known today that scattering phenomena in multilayer coatings are of great importance, and we have already shown how and why it was necessary to understand in detail these mechanisms if we want to increase the performance of optical systems. Among the numerous parameters involved in the calculation of the scattered wave (roughness, autocorrelation lengths, cross-correlation coefficients, indices, and thicknesses of the layers, …), the cross-correlation laws inside the stack play an essential role, because they are largely responsible for the form and the magnitude of the flux scattered from a coating. Moreover, their knowledge leads to precious information concerning the fine microstructure of the materials in thin-film form. We first show how some specific effects such as the antiscattering effect) enable us to determine the cross-correlation laws for a coating with a small number of layers, and a carefully done comparison between theory and experiment is used to characterize the fine microstructure of the materials. For a coating with a great number of layers, the phenomena are more complicated to interpret. Nevertheless, an investigation is sometimes possible, and we present our results for a mirror and a Fabry-Perot filter.

© 1986 Optical Society of America