Nonlinear cross talk between gratings recorded in BaTiO3 by mutually incoherent beam pairs

Abstract

The nonlinear cross talk between two photorefractive gratings recorded in a BaTiO 3 crystal has been investigated. Besides the photorefractive response described by the material equations, our theoretical analysis also includes the effect of beam coupling through the coupled-wave equations. We show that beam coupling has a strong influence on the nonlinear cross talk in BaTiO 3 . Depending on the initial conditions, it may lead to an increase or decrease of the nonlinear grating cross talk. Moreover, our experimental results provide experimental evidence of nonlinear cross talk in BaTiO 3 . Significant cross talk values, up to ϳ20%, have been found experimentally. Furthermore, the experimental data are in good agreement with the theoretical predictions. The results have relevant implications in practical situations such as sequential recording of holograms for holographic storage.