Comparison of computer-generated holograms produced by laser printers and lithography: application to pattern recognition

Binary computer-generated holograms have been produced using different output displays, with different techniques, resolutions, and material substrates. Laser printers, commercial high-resolution laser writers, and lithographic techniques have been used. A combined technique based on the photoreduction over a lithographic plate of a mask generated by a high-resolution laser writer is proposed. We have studied the impulse response of such holograms and their performance with a view to their use as filters in correlation setups for pattern recognition. The results obtained show that lithographic techniques improve the quality of the holograms. The holograms obtained with the combined technique are comparable, for this application, to those etched directly onto the lithographic plate.