Investigation of the Influence of the Quality of Surfaces of Optical Substrates on the Performance Characteristics of Thin-Film Coatings

The main results of the operation of a modern technological system for the deposition and control of optical coatings on substrates with different degrees of roughness are analyzed according to the data of recording the characteristics of the scattered laser radiation indicatrix. The features of the approximations of the differential scattering method used to estimate the statistical parameters of the profiles of optical substrates are considered: the spectral density of the correlation function (SDCF) and the effective standard deviation (root-mean-square or RMS). The main characteristics of the scattered laser radiation from the surfaces of optical parts with different levels of roughness are presented. The results of experimental studies devoted to the influence of the quality of the surfaces of optical substrates on the performance characteristics of various film-forming materials of optical coatings applied with and without ion assistance are discussed. Based on the experiment carried out, the possibilities of reducing light scattering and leveling the irregularities of the surfaces of substrates with different degrees of roughness are investigated.