MEASUREMENT OF THE SPATIOTEMPORAL RESPONSE OF PHOTOREFRACTIVE CONJUGATION

We have examined the process of photorefractive four-wave mixing when the probe and forward-pump waves contain time-varying images. In the f irst-order perturbation theory, the conjugate image is related to the probe and forward pump images by a bilinear relationship in time and s pace, which is characterized by a transfer function., We have measured this transfer function, and the experimental results agree with theor y. We have also observed the fidelity of a photorefractive correlator when one of the images is moving with a constant velocity, and compare d the results with theoretical predictions.