Disk-based optical correlator and method

摘要

The correlation speed and storage capacity of an optical disk-based correlator is enhanced by employing a thick (several hundred micron) photo- polymeric film (or other thick holographic media) on the disk as the recording media to permit volume holography and angular multiplexing of holograms in each spot on the disk. For example, if 100 holograms are multiplexed at one spot, 100 1-dimensional correlation functions can be read in parallel off of the disk while illuminating it with a single input image. The diffraction of the image beam by the recorded holographic patterns occurs at the holograms in the disk. The full 2-dimensional correlation function for each one of the holograms stored in a given spot on the disk is generated line-by-line a follows: By imaging in the along-track direction of the disk and Fourier transforming in the radial direction of the disk when both recording the template image hologram and presenting the input image to the recorded hologram, disk rotation generates the two-dimensional correlation functions between stored template images and the input image. All correlation functions for holograms angularly multiplexed at a given spot are generated line-by-line and detected in parallel along adjacent line detectors in the off-disk correlation plane.