Dynamic behavior of spatial bright solitons in a biased transversely shifting photorefractive crystal

We have observed and simulated the dynamic evolution of a beam launched into a biased transversely shifting photorefractive crystal. Propagating in this scheme, the beam can trap into spatial solitons and then deflect to the beam shifting side. The deflected amplitude of solitons relates to the shifting velocity of the sample (beam). At a higher shifting velocity, the bending amplitude of the beam will be decreased. We attribute this bending to the nonlinear relaxation effect present in the samples. The experiment and the simulation show fairly good agreement.