Optical implementation of a photorefractive joint transform correlator with wavelet filters

We have investigated a real-time photorefractive joint transform correlator (JTC) with a bank of wavelet filters. In the experimental set-up, a photorefractive crystal BSO has been used as the dynamic holographic medium and a bank of discrete wavelet functions, derived from a mother Mexican-hat wavelet have been selected to achieve band-pass operations in the JTC Fourier domain. With the proper dilation factors, shaper correlation peaks, higher discrimination ability and higher noise robustness have been obtained. Experimental results and analysis are presented.