Abstract

Photorefractive two wave mixing has many potential applications in the areas of optical image processing, optical interconnection, and optical computing. However, because of the presence of the fanning effect, the achievable two wave mixing gain and the signal to noise ratio are severely limited in those crystals with high coupling coefficients, such as BaTiO₃, KNbO₃, SBN, etc. It is important to reduce the fanning noise for practical applications. Several methods have been proposed.^1,2 In this talk, we present a simple and effective approach to suppress the fanning noise and to increase the signal to noise ratio by introducing an incoherent erasure in the photorefractive two wave mixing amplifier. With the incoherent erasure, the achievable gain and the signal to noise ratio can be improved significantly. Results from theoretical modeling and experimental investigation in a 45°-cut BaTiO₃ crystal will be presented and discussed.

© 1992 Optical Society of America