PROPAGATION OF LIGHT-BEAMS IN PHOTOREFRACTIVE MEDIA - FANNING, SELF-BENDING, AND FORMATION OF SELF-PUMPED 4-WAVE-MIXING PHASE-CONJUGATION GEOMETRIES

We investigate propagation of light beams in photorefractive media by direct numerical simulation. The two dimensional model is based on solution of nonlinear material equations and parabolic equations for the electromagnetic field. We show that this set of equations describes the wealth of complicated spatial structures observed in these media. We present results on fanning of a single beam and on formation of various four-wave-mixing geometries including self-conjugation of a light beam via total internal reflection, mutual phase conjugation, and self-bending of two counterpropagating beams.