Transient self-bending of laser beams in photorefractive crystals with drift nonlinearity

Abstract

Another optical nonlinear effect is reported: the transient self-bending of a laser beam within a photorefractive crystal under an external electric field. It is based on the large drift length of the photoinduced carriers and is observed during a transient regime immediately after applying the light beam. Results of a numerical simulation are supported by an experimental demonstration of the effect in cubic ${\mathrm{Bi}}_{12}$Ti${\mathrm{O}}_{20}$ at $\ensuremath{\lambda}=633$ nm.