Digital correlation hologram implemented on optical correlator

A new kind of computer-generated hologram termed digital correlation hologram (DCH) has been developed and demonstrated with promising results. This hologram is composed of two separate sub-holograms. The reconstructed image is obtained as a result of a spatial correlation between the hologram's two parts. The DCH codes two complex functions which are generated by an iterative optimization procedure. The correlation between the two sub-holograms is implemented by means of a joint transform correlator (JTC). When the double-elements hologram is displayed on the JTC input plane, and illuminated by a plane wave, a desired image is constructed on part of the correlator output plane. The DCH can be used for security and encryption systems, as the desired image will be received in the output plane only when the two specific sub-holograms are placed at the input plane of the JTC. Simulation and experimental results demonstrate the suggested technique.