MAXIMIZED PHOTOREFRACTIVE HOLOGRAPHIC STORAGE

Recording angularly multiplexed holograms in photorefractive media requires an understanding of both the recording and erasure dynamics. In this paper a coupled-wave analysis is used to describe both the recording and erasure processes. This analysis has been applied to the recording of multiplexed holograms, resulting in a procedure to record maximum diffraction efficiency holograms. Experimental results confirming the theory for both the dynamics of a single exposure and the efficiencies of multiple exposures are presented. Using an uncoupled recording wave analysis, an expression for the dependence of the diffraction efficiency on the number of exposures in the case of equal record/erase time constants is presented. Approximate results are presented for the case of unequal time constants. This serves to set an upper limit on the diffraction efficiencies for a given saturation index of refraction modulation.