Abstract

We explore phase conjugation of transient optical signals through the mechanism of degenerate four-wave mixing in photorefractive media. Our model is governed by Maxwell’s equations for the transient optical fields, coupled with Kukhtarev’s¹ diffusion equations for the material variables, under the assumptions of slowly varying envelopes and strong undepleted sinusoidal pumps. The resulting linear partial differential equations for the wave envelopes are solved via Laplace transform techniques in time. An explicit expression for the transfer function of the conjugator is obtained, and the related impulse response function is found by performing numerically an inverse Laplace transform. The conjugate signal is then expressed as an integral expression involving the probe signal and impulse response function. The effects of material parameters, an applied steady electric field, the total pump intensity, and the asymmetry of the pumps on the stability and performance of the conjugator are assessed.

© 1987 Optical Society of America