We experimentally investigate the effect of light self-focusing in a photorefractive Rh-doped SBN crystal. The self-focusing is caused by partial screening of an externally applied electric field within a small illuminated region. With a proper choice of the experimental parameters a nearly constant soliton width for a large range of the nonlinearity can be obtained. We believe that this effect is connected with trapping of the ordinarily polarized background light in the soliton-induced waveguide, which reduces the intensity ratio inside the sample and therefore can lead to stabilization of the one-dimensional bright solitons. The influence of this effect on soliton propagation is discussed using a simple theoretical model.

© 2001 Optical Society of America