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Compact 4-D Optical Neural Network Architecture

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Final rept. 15 Aug 1989-15 Apr 1990

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This Final Report describes the results of a Phase I SBIR project to investigate 4D optical interconnects recorded in inhomogeneously broadened absorbers. Our concept has the potential to provide much large numbers of interconnects than can be achieved using electronics. The need for an extremely large number of interconnects was considered in a recent DARPA-sponsored study. There are a number of applications which might require more interconnections than can be realized using electronics about equal to a dumb honeybee. For example, vision applications, including infrared search and track, may require more than 10 to the 10 power interconnects and 10 to the 13 power interconnects per second. Our interconnect architecture makes use of holographic interconnects stored in spectral hole burning SHB materials. The use of holography provides access to a volume of material to achieve a very large storage capacity of interconnect values. The work described here makes use of presently available materials in new ways. Our 4D concept is based on the unique properties of spectral hole burning materials. In addition to the three spatial dimensions available using volume holographic techniques, a fourth, independent dimension, laser frequency is available. This independent dimension is achieved by using materials capable of recording information at one specific laser wavelength which cannot be seen by any other wavelength. By making use of additional laser wavelengths, information can be stored and read independently at many laser wavelengths. In this report we also discuss a second recording mechanism using index of refraction changes which has important advantages for the available spectral hole burning materials.

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  • Cybernetics

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