Compact Optical Associative Memory Using Dynamic Holographic Storage Media and Photorefractive Gain and Attenuation Elements.

摘要

This research effort implemented a compact optical associative memory architecture consisting of a Fabry-Perot Confocal Resonator (FPCR) optical processing environment, two dynamically reprogrammable Lithium Niobate volume holograms, and Barium Titanate gain and attenuation elements. The reduced physical dimensions of the compact optical processing environment make it more adaptable to military applications than previous associative memory designs. The FPCR employs Mangin mirrors designed to reduce spherical aberrations in off-axis rays. The orientation of the gain element's grating vector angle and the model used to predict the profile of the attenuation element were unique to this research effort. The object stored in the associative memory was phase encoded using a glass microscope slide etched in a 40% hydrofluoric acid solution. Beam path deviations caused by the non-parallel geometry of the photorefractive crystals were corrected with a variable pitch, plate glass optical wedge inserted in the cavity's feedback arm. Experimental results showed the system is capable of storing and fully retrieving a single object from memory when presented with partial information about the object Additional system modifications are required to store and retrieve multiple objects. Theses. (RRH)