Correlation properties of random phase diffusers for multiplex holography.

Random phase diffusers used to individually code the reference beams employed in multiplexing a set of holograms are best characterized by their autocorrelation and cross-correlation properties. In this paper multilevel (n-level) phase diffusers and ground-glass diffuser models based on a spatial random telegraph wave are employed to investigate the performance of such diffusers for both plane wave and spherical wave illumination. The advantage of using balanced phase diffusers is indicated, and it is shown that a binary phase diffuser can, in principle, perform as well as a multilevel (n > 2) diffuser, and even as well as ground glass if the spatial fineness of the diffusers is comparable. Two signal-to-noise ratio measures of the performance of the various diffuser systems in a multiplex holography application are evaluated and discussed.