DETERMINATION OF PLATES DIELECTRICAL SURFACES CHARAKTERISTICS BY LIGHT SCATLERING

Abstract

The paper proposes a new method for determining the roughness parameters and the correlation function (CF) of supersmooth dielectric plates. The method is based on finding the expansion coefficients (CF) from the experimental light scattering indicatrix in a series according to a system of orthogonal functions, followed by the calculation of the standard deviations of the surface irregularity heights σ and the correlation period Т. Distinctive features of the method are: 1) the absence of ambiguity that arises when fitting theoretical dependences with different correlation functions, which themselves depend on the roughness parameters, to the experimental scattering curve; 2) the possibility of avoiding the need to measure the scattering indicatrix in the entire hemisphere above the sample. This method for determining the CF and surface roughness parameters can be used for any type of interface, subject to the Rayleigh criterion, which determines the degree of roughness of the reflection surface with respect to the wavelength of the incident radiation. Therefore, the objects of study can be not only surfaces with nanometer roughness irradiated by laser light, but also, for example, earth covers during their remote sensing by radio signals from navigation satellites. For polished quartz plates, the values of the surface parameters were obtained close to similar values measured independently on a laser interference profilometer by other authors.