Dynamic phase-encoding storage of 64 images in a BaTiO3 photorefractive crystal

Abstract

Storage of 64 images (128 x 128 pixels) by the deterministic phase-encoding technique in a holographic memory is reported. A ferroelectric phase modulator permits a fast random image reconstruction (150 As/image). Sources of cross talk arising from the imperfections of the optical components are studied and evaluated. We present a photorefractive (PR) memory setup that permits the storage of N = 64 images of 128 X 128 binary pixels in a BaTiO3 crystal by the deterministic phase-encoding technique.`-4 Because of the absence of any moving mechanical parts this multiplexing method permits a reliable and very fast random access to the images. This memory could be used in digital computing or for pattern recognition.' This technique consists of recording the N images by interference of the image beam with all N reference beams. These beams are angularly spaced by more than the Bragg angle so that each of them reconstruct