Instability and optical turbulence in the formation of spontaneous gratings in single-mode photosensitive AgCl-Ag films

In experiments on illumination of thin photosensitive AgCl films containing granular Ag by a focused laser beam (lambda = 633 nm), self-pulsations in the form of optical turbulence were found and studied. In the course of ill umination, the turbulence was observed in the pattern of small-angle scatte ring in the form of "boiling" of light spots separated by dark spacings. Th e formation of turbulence is associated with spontaneous microgratings, who se origin involves waveguide TE modes scattered in a film, and their compet ition in the course of illumination, which leads to the growth of one micro gratings and the decay of the other. (C) 2000 MAIK "Nauka/Interperiodica".