Photorefractive-material-based pattern recognition using fringe-adjusted correlation

The application of photorefractive materials has shown remarkable promise over the last two decades for various computation-intensive information processing applications such as pattern recognition. In this paper, we explore various two-beam coupling and four-wave mixing architectures and algorithms for all-optical implementation of real time pattern recognition techniques suing photorefractive materials. The application of novel concepts such as the incoherent-erasure fringe-adjusted joint transform correlation, obscured target detection, heterogeneous correlation and nonlinear compansive noise reduction for enhancing the correlation performance are discussed in detail. The trade-offs between various performance criteria such as correlation peak intensity, efficiency and noise performance has been investigated.

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