Compact planar optical correlator.

A compact planar configuration for performing optical correlation is described. It comprises two pairs of identical holographic lenses and a holographic filter. Each pair of lenses is recorded on a single substrate; together the lenses perform exact Fourier transformation. The light between the lenses propagates inside the substrate by total internal reflection. The design and recording considerations for each of the elements along with experimental results for the overall planar correlator are presented.