Abstract

Current research and development in optical imaging, computing, communication and signal processing and switching have focused considerable efforts on highly efficient nonlinear optical and electro-optical materials. In combination with novel nonlinear optical processes and cw or pulsed lasers covering a wide spectral range, several useful practical devices have been developed. In particular, optical switching elements and logic gates^1,2, infrared-to-visible image converter, real time image correlators, image or beam amplifiers³, nonlinear guided wave structures, optical memory devices (e.g., associative memory by phase conjugation⁴) and various beam steering and beam combining devices⁵ have been proposed and demonstrated. Concommitant to these device developments, optimization procedures and system requirement considerations have narrowed the "ideal" nonlinear optical materials to a few classes, such as semiconductors, photorefractive crystals and organic materials⁶. Several of these materials are still in the research phase, although they have been shown to possess many desirable characteristics (such as high speed and low energy requirements).

© 1988 Optical Society of America