Fringe-adjusted incoherent erasure joint transform correlator

A new all-optical nonlinear fringe-adjusted joint transform correlation (JTC) technique is proposed. The proposed scheme is based on incoherent-to-coherent conversion with the erasure of a four-wave mixing arrangement in a real-time photorefractive media. This technique is very fast because it generates the correlation output in one step and all intermediate processing is performed in the optical domain. Furthermore, this technique eliminates the problems due to nonlinearities associated with the square-law devices and spatial light modulators used for recording the joint power spectrum. Computer simulation results show that the proposed joint transform correlator yields superior performance when compared to the alternative joint transform correlator architectures. (C) 1998 Society of Photo-Optical Instrumentation Engineers. [S0091-3286(98)02001-7].