Dynamic electrooptic effect induced by space charge waves in sillenites

In photorefractive sillenite-type crystals we discovered that a temporally oscillating but spatially homogeneous space charge field arises if we illum inate 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 po larization of a transmitted probe beam, i.e., via the dynamic electrooptic effect which is induced by this spatially homogeneous space charge field. I t 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 demo nstrated. (C) 2001 Published by Elsevier Science B.V.