Influence of current anisotropy on self-focusing in photorefractive crystals

Abstract

Summary form only given. Photorefractive ferroelectrics have quite strong anisotropy of photocurrent. In barium titanate the typical ratio between conductivities in a- and c-directions is 14-20:1. In strontium barium niobate (SBN) this ratio is 1:3, ie. in this crystal the conductivity is higher along the c-axis, whereas in BaTiO/sub 3/ it is higher along the a-axis. Previous analysis of circular beam self-focusing (2D screening solitons) was not taking this factor into account. We demonstrate numerically that the existing anisotropy can dramatically affect the shape of self-focused beam.