Transient behavior of the photorefractive space-charge field

The transient behavior of the fundamental amplitude of the photorefractive space-charge field is derived without restrictions within the band transpor t model. The two-wave mixing pulse excitation regime is simulated in differ ent ranges of the main parameters, especially in the region where the nonli near processes become important. The formation and decay of the field are a nalyzed, and for different ranges of the excitation parameters the correspo nding behaviors are predicted. Features of the field such as the nonlinear decay of the photorefractive field at high-writing pulses, its oscillatory behavior when an external field is applied, and the dependence of its forma tion and decay time on the grating spacing are studied.