Nobuyuki Kasama

Effects of nonlinear parameters in feedback joint transform correlator (I)

We report that nonlinear parameters effect the characteristics of the optical pattern recognition of a feedback joint transform correlator (FJTC) which is based on a joint transform correlator (JTC). This system incorporates the optically addressed ferroelectric liquid crystal spatial light modulator named LAPS-SLM. Nonlinear parameters in the FJTC are a threshold level of the LAPS-SLM to record the binary joint power spectrum (JPS), and a feedback transfer function from the correlation plane to the input plane. It is important to control the threshold level of the binary JPS. But the FJTC does not always need the optimum condition where the FJTC recognizes the signal image correctly at the initial recognition.

Catastrophic characteristics of pattern recognition in feedback joint transform correlator

A joint transform correlator with feedbacks from the correlation outputs to the input intensity of the reference images works as a neurocomputing system. The characteristics change catastrophically with the parameters of the feedback transfer function.