BRIGHT LIGHT DOTS CAUSED BY INTERFERENCE OF PARAMETRIC SCATTERING PROCESSES IN LINBO3 CRYSTALS

Propagation of two extraordinarily polarized pump beams in LiNbO3:Cu c rystals leads to a complicated pattern of photoinduced scattering on a viewing screen behind the sample. This pattern includes a considerabl e number of light rings and unclosed lines, and at some of the interse ctions bright light dots appear. For a scattering distance of a few mi llimeters the dots can contain most of the transmitted light intensity . Our theoretical study indicates that the light dots are caused by co nstructive interference of four different processes of parametric scat tering. We show within the photovoltaic transport model that such an i nterference may increase the rate of exponential growth of the seed wa ves by a factor of 1.5-2. Good agreement between theory and experiment is demonstrated. (C) 1996 Optical Society of America.