Three-dimensional analysis of code processing in photorefractive holographic memory

We have proposed an all-optical memory with authentication and unlawful access detection using photorefractive four-wave mixing. If the data is read out by the reading beam with the improper key, the output intensity is scarcely zero and any output isn't obtained. Therefore we can judge at a glance whether or not the used decoding key is the proper key. We analyze the diffraction efficiency with consideration of the phase mismatching to evaluate the fidelity of the hologram. In this analysis, we examine the property of the crystal that depends on three-dimensional coupling coefficient. We simulate the encoding and decoding process with some image data in this all-optical memory with authentication and unlawful access detection. We show that the encoded image is restored to its original image in case of retrieving with the proper key, on the other hand the retrieved image of which intensity is scarcely zero is obtained in case of retrieving with the improper key.