Encrypted optical storage with angular multiplexing

We present the first, to our knowledge, demonstration of an encrypted optic al storage based on double-random phase encoding by using angular multiplex ing in a photorefractive material. Original two-dimensional data are encryp ted by use of two random phase codes located in the input and the Fourier p lanes and are then stored holographically in a LiNbO3:Fe crystal. The retri eval of the original data can be achieved with a phase-conjugated readout s cheme. We demonstrate the encryption and the decryption of multiple frames of two-dimensional digital data by using angular multiplexing. We also eval uate numerically the influence of the bandwidth of the optical system on th e decrypted digital data. The bit error rate as a function of the optical s ystem bandwidth is presented. (C) 1999 Optical Society of America.