FORMATION OF SPATIAL SOLITONS AND SPATIAL SHOCK-WAVES IN PHOTOREFRACTIVE CRYSTALS

An analytical model, which describes the drift and diffusion mechanism s for the formation of the nonlinear response (local and nonlocal nonl inearities) of photorefractive crystals on the microscopic level, is c onstructed. New types of stable self-consistent distributions of the l ight field intensity, i.e., spatial solitons, are found. The trajector ies of their motion (self-bending) are calculated, and the possibility of observing a new nonlinear-optical effect in photorefractive crysta ls, viz., the formation of spatial shock waves, is demonstrated. The m odulation instability appearing when plane waves propagate in photoref ractive crystals is analyzed, and the characteristic spatial scales of the light field distribution formed as a result of self-interaction ( fanning) are determined. The results of the analysis are confirmed by computer simulation data. (C) 1997 American Institute of Physics.