Cross-talk noise and storage capacity of holographic memories with a LiNbO₃ crystal in the open-circuit condition

A solution to the Kukhtarev equations is obtained for a typical holographic memory system in which multiplexed holograms, including the effects owing to a nonuniform beam profile in the focal regions, are used. The various noise mechanisms and storage capacity are analyzed on the basis of this solution. The cross-talk noise of a typical 4f holographic memory configuration with defocus is compared with that of a phase mask. It is shown that the memory capacity and the signal-to-noise can be significantly improved by design of an optimal phase mask. The experimental results with defocus and an eight-level phase mask are presented.