Associative holographic memory with feedback using phase-conjugate mirrors

A parallel optical associative memory system with feedback that is implemented with holograms and nonlinear optical elements is described. The global memory, a hologram, is capable of storing multiple three- dimensional objects, thus overcoming one of the limitations of the matrix- based approach. The nonlinear interaction is achieved by the use of phase- conjugate mirrors to provide the regenerative feedback, thresholding, and amplification mechanism. Results of preliminary experiments are discussed. (B.J.)