Abstract

Spatial solitons in photorefractive media have been the subject of intense theoretical and experimental investigations [1]. One of the first experimental demonstrations of self-focusing and self-defocusing effects has been done in cubic barium titanium oxide (BTO) crystal [2], where the so called screening solitons [3] have been observed. The cubic crystals are attractive because for some crystallographic orientation, the optical beam either experiences self-focusing or self-defocusing, depending on polarization. Thus, for fixed direction of the biasing electric field, bright, dark or coupled bright and dark solitary beams are possible. However, some cubic crystals exhibit strong natural optical activity (OA) which is 6.3°/mm for BTO. Since the photorefractive nonlinearity strongly depends on polarization, polarization rotation may destroy the soliton propagation. In the present work, we examine the influence of optical activity on propagation of screening solitons in cubic PR crystal.

© 1996 Optical Society of America