This paper discusses the imaging properties of discrete holograms with modified structure—i.e., discrete holograms characterized by an amplitude transmission function that does not contain a term that describes the halo—i.e., the term caused by the mutual interference of the waves generated by various points of the object. Starting from the requirement of spatial separation of the orders of diffraction of such a hologram, the limiting allowable frequency bands are established for the object wave and the hologram as a whole. It is shown that it is possible to increase the resolving power of discrete holograms by modifying their structure. It is established and theoretically substantiated that it is impossible in principle to record discrete holograms with spatial frequencies that exceed the Nyquist frequency of the hologram recorder—for example, a photodetector array. Recommendations are given for putting into practice the effect of substitution of spatial frequencies intrinsic to discrete holograms when recording digital holograms and reconstructing synthesized holograms.
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