Abstract

We describe a computer modeling technique for calculating photorefractive grating formations in which the chage redistribution and grating formations are calculated by means of a finite-element approach. This method provides time-dependent field and charge distribution characteristics without requiring the small-modulation-index approximation. This approach can be applied to both cw and pulsed laser interactions. The computational time required to model picosecond and nanosecond grating formations is minimal, but the computational time to model cw laser interactions is usually substantial. However, a "quasi-steady-state" approximation can often be applied, which reduces the computational time significantly. This approximation allows the calculation of the steady-state field and charge distributions and in many cases still provides useful time- dependent information.

© 1990 Optical Society of America