AN EFFICIENT METHOD OF IMPLEMENTING NEAR-FIELD DIFFRACTION IN COMPUTER-GENERATED HOLOGRAM DESIGN

A new method is introduced for representing near-field scalar diffract ion in the context of computer-generated hologram design. This method is computationally efficient and allows existing design algorithms for Fraunhofer holograms to be adapted to the design of near-field hologr ams. Results of applying this method to the simulated annealing algori thm are shown, along with a discussion of design and performance consi derations peculiar to the near field. In particular, we have found nea r-field holograms to be less efficient and to form images of poorer qu ality than Fraunhofer holograms designed with the same underlying algo rithm. Our studies suggest this may be an inherent difficulty in near- field hologram design. (C) 1997 Elsevier Science B.V.