Influence of different recording parameters when reconstructing an hologram

Abstract

This paper deals with the influence of emulsion thickness and absorption as well as the different recording parameters when reconstructing an hologram. The hologram of a plane wave recorded with a parallel reference beam is a set of equidistant layers inside the emulsion. When reconstructing this hologram, each layer acts as a narrow mirror, with a broad diffraction lobe. However, the large number of layers produces a «grating effect» and constructive interference occurs in only one direction, that corresponding to the reconstructed image. When the reconstruction beam has a different direction or wavelength than that of the reference beam, the angular or chromatic selectivity has been worked out taking into account the different rotations undergone by the diffraction direction and grating effect direction. The influence of emulsion shrinkage and absorption is also studied. It is shown that absorption has a great importance for back carrier holograms, but is negligible for transmission hologram.