Numerical modeling of photorefractive response to short-pulsed illumination

Numerical modeling of the nonlinear response of non ferroelectric photorefractive crystals to short-duration laser pulses is demonstrated. The model is based on the band-transport equations for a single-level, single-charge carrier system. The capabilities of the numerical model surpass the capabilities of linearized theories. The accuracy of the model is demonstrated by comparison with published diffraction efficiency data. The growth of the harmonics of a unity-modulation sinusoidal grating and the response of Bi(12)SiO(20) to multiple Q-switched pulses are two examples that demonstrate how the numerical model surpasses the linearized theory. Comparison with experiment dictates that a sinusoidal grating be assumed, but the model is general enough to accommodate arbitrary patterns of incident energy density.