NONLINEAR DYNAMICS OF A 2D FEEDBACK-SYSTEM WITH PHOTOREFRACTIVE GAIN

We introduce a liquid crystal light valve (LCLV) based nonlinear optic al system having a two-wave mixing photorefractive amplifier in a two- dimensional (2D) diffractive feedback loop. Experimental results demon strate evidence of suppression of the influence of phase distortions c aused both by the gain medium and by input beam (signal and pump) wave front aberrations. When system feedback field intensity was increased we observed the formation of hexagonal transverse patterns. An increas e in total intensity inside the photorefractive media resulted in the appearance of self-induced traveling waves.