Photorefractive correlators for optical pattern recognition and object motion measurement: some improved techniques

摘要

This paper reports the outcome of research studies carried out by us in the area of Optical Pattern Recognition. We describe experimental realization of two kinds of all-optical nonlinear photorefractive (PR) joint transform correlators. One method uses a controllable beam-fanning nonlinearity and the other uses an incoherent erasure beam in PR wave-mixing. An experimental technique has been demonstrated to achieve high pattern discrimination using a bank of wavelet filters. Correlation technique has further been extended to real-time object motion measurement.