Diffraction Theory of Holography

Abstract

A diffraction theory of side‐band holography for transmission objects is formulated. Conditions are derived under which good quality images are formed. A simple geometrical construction is found by means of which the location of the images may be determined. It is also shown that, under conditions that are often satisfied in practice, one of the two images will be completely absent. This effect is entirely caused by diffraction (conversion of a homogeneous wave into evanescent waves on diffraction by the hologram) and has nothing to do with the finite resolving power or the finite thickness of the photographic plate. Numerical examples illustrating this phenomenon are given.