Influence of Photovoltaic Effect on Photorefractive Phase Gratings

We solve the Kukhtarev’s nonlinear equations of the photorefractive effect with the participation of diffusion, drift and the photovoltaic effect without the approximation of linear generation and linear recombination, and especially discuss in detail the effects of photovoltaic field on the photorefractive grating and its equivalence to an applied electric field in the photovoltaic photorefractive materials.