Phase Conjugate Optics.

The purpose of this program has been the study, both theoretically and experimentally, of the use of phase conjugate optics for information processing and image transmission applications. A significant portion of effort was directed toward an improved understanding of the photorefractive effort and its application to two-wave and four-wave mixing. The authors developed a model for grating formation in photorefractive materials and have derived expressions for figures of merit, which aid in selection of materials and the optimization of efficiency and speed. They also developed a model for two-wave mixing in the transient regime, and measured response times for both tow-wave and four-wave mixing. Other devices and materials considered for ODP applications include the Hughes liquid crystal light valve and long-chain organic molecules. Measurements on several ODP configurations were performed. First, they used optical phase conjugation to transmit an image through a 1.75 m multimode fiber, with a resolution of better than 15 linesmm. Secondly, they demonstrated several static convolution and correlation operations, using character masks. Finally, they investigated the use of phase conjugation for real-time optical correlation. Results of each of these experiments are described. Author