Abstract

In this work we show that a simple, but efficient, way to obtain single-pulse phase conjugation in a photorefractive crystal is to use self-pumped four-wave mixing¹ Here, self-pumped phase conjugation of a pump beam, which consists of a train of pulses, is allowed to develop over a long period of pulsed illumination and is used to generate automatically self-aligned counterpropagating pump beams for the four-wave mixing of a single signal pulse incident in the same crystal. We present here the results of such a simple single-pulse phase conjugator using pulses of several megawatts per square centimeter. We observe the dark evolution of gratings written at these intensities and study their behavior both experimentally and theoretically.

© 1995 Optical Society of America