Dynamic electrooptic effect induced by space charge waves in sillenites

Abstract In photorefractive sillenite-type crystals we discovered that a temporally oscillating but spatially homogeneous space charge field arises if we illuminate the samples with a spatially oscillating interference pattern formed by two coherent plane light waves. This field is of the order of 50–60 V/cm and we investigate it via measurements of its influence on the state of polarization of a transmitted probe beam, i.e., via the dynamic electrooptic effect which is induced by this spatially homogeneous space charge field. It is shown that the reason for the occurrence of the space charge field is a nonlinear interaction of space charge waves. Very good agreement between the experimental data and results of the proposed theoretical model is demonstrated.