Wavelength coded image transmission and holographic optical elements

The results of a three year optics research program are described. Research was initially performed on wavelength coded image transmission. The goal of the program was to study various methods and systems for encoding object information in a wavelength multiplexed form so that the various wavelengths could be transmitted through a non-imaging media such as fog or a fiber optic and later spatially repositioned to reassemble an image of the original object. Such a system could be used to transmit image information at higher data rates and/or to transmit images through fewer optical channels. During the second year, the program was augmented to include research on a new type of holographic optical element called a multifact hologram. Such holograms consist of a large number of small, adjacent holograms (facets) which collectively diffract light to produce a desired output. These elements share some of the flexibility advantageous to Computer Generated Holograms with the high optical efficiency inherent in interferometrically recorded volume holograms. A computer controlled recording system was built to fabricate these elements. A number of space-variant image operations not possible with conventional optics were demonstrated using multi-facet holograms.