An incoherent optical correlator based on photoanisotropy

We describe theoretically the function of a nonlinear optical element based on photoanisotropy in azo-dye-doped polymers for optical correlation. This element allows the realization of a matched filter with two incoherent lig ht beams. The described technique involves the insertion of a photoanisotro pic polymer sample in the Fourier plane of the optical element. Due to the specific features of photoanisotropic materials the output is characterized by the convolution of the first wave with the autocorrelation function of the second wave.