Diffraction mechanism of periodic structure formation under the action of radiation on an absorbing condensed medium

The problem is considered of the diffraction of a high-power optical wave by a periodically rippled surface of an absorbing medium. It is shown that the diffraction by inhomogeneities of the surface, or of the layer of the medium adjacent to it, can produce a periodic structure on the surfaces of dielectrics, semiconductors, and metals. Calculations are employed to determine the ranges of variation of the optical constants of different media ensuring the formation of surface gratings with grooves perpendicular or parallel to the electric vector of the incident wave.