Holographic high order associative memory system

The authors have demonstrated the use of two dimensional arrays of Fourier Transform holograms in an opto-electronic implementation of a high order feedback net (HOFNET). The nonlinearity in this net is produced by means of feedback and not by optical material nonlinearities and so the net is not limited by the switching speed, non-uniformity or availability of large arrays of opto-electronic nonlinear neurons. Spatially multiplexed holograms offer the advantages of no cross coupling, convenient addressability and, if formed in a photorefractive material can be selectively erased and updated without interfering with other memories