Abstract
The growth of spontaneous periodic structures (SPS) in thin photosensitive AgCl-Ag films deposited on a calcite single crystal was studied under the influence of laser radiation. Features in the formation of SPS associated with the anisotropy of the substrate were discovered: the growth of spontaneous gratings at small film thicknesses due ti the excitation of extraordinary waves in the substance, the azimuthal dependence of the period and amplitude of gratings growing on the limiting TE modes with the wave vector.