dispersion of optical waves
spatial structure of a field
Results of experiments on research of structure of a field of an optical range in various areas of the space disseminated by slabosherokhovaty surfaces, show various "speed" of formation of stable spatial ranges depending on distance to the scatterer. Comparison of these results to data of direct measurement of correlation lengths of studied samples showed that the structure of a diffused field starts to correspond to structure of a field, characteristic for a distant zone, at smaller distances for surfaces with smaller correlation length.
The work purpose – definition of an analytical type of the dependence connecting a distance of formation of a distant zone of a diffused field with parameters of the scatterer.
As a result of researches it is possible to conclude that transition to this or that limiting case occurs as at change of degree of a roughness of a surface of the scatterer, and at change of the size of its aperture. It explains results of the experiments showing possibility of detection of low-dimensional defects on a surface with a small roughness, a way of registration of spatial ranges disseminated by defects radiations at such small distances from a surface on which the field disseminated by the surface doesn't reach still borders of the of «a distant zone» and represents actually unstructured noise to a component.