E-beam written computer generated holograms

This final report describes a three-year research program to investigate computer generated holograms produced by electron beam lithography. Because they are light weight and can create wavefronts of arbitrary complexity, computer generated holograms are attractive for applications such as optical data processing and optical testing. To be practical, these elements must have large space-bandwidth products, and have the qualities of high diffraction efficiency, low scattering, low aberration and low cost, as compared to conventional optics. Developed have been generalized encoding algorithms and fabrication techniques for producing e-beam computer generated holograms having submicron feature sizes, distortion-free resolution of better than 0.4 micron, and space-bandwidth products in excess of 10 to the 7th power. E-beam lithography is superior to optical plotting for writing computer generated holograms and, with further refinement, could be extended to produce holograms having space-bandwidth products as large as 10 to the 11th power, comparing favorably with interferometrically recorded holograms.