Secure optical storage with random phase key code based on joint transform correlator architecture

Abstract

An encrypted optical storage based on a joint transform correlator architecture by using a photorefractive material is presented. A key code designed by optimized algorithm so that its Fourier transform has a uniform amplitude distribution and a random phase distribution is introduced. Original two-dimensional data and the key code are placed side by side at the input plane. Both of them are stored in a photorefractive material as a joint power spectrum. The retrieval of the original data can be achieved with the same key code. We can record multiple two-dimensional data in a same crystal by angular multiplexing. Furthermore we can record by key code multiplexing because another designed key code can produce another independent phase distribution. We demonstrate the concept of the optical data storage system by computer simulations.