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Optical Engineering

Position, Scale, And Rotation Invariant Holographic Associative Memory
Author(s): Kenneth H. Fielding; Steven K. Rogers; Matthew Kabrisky; James P. Mills
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Paper Abstract

An all-optical holographic memory was recently proposed by researchers at the Hughes Research Laboratories. This paper details the investigation into the characteristics of that system and an extension to a position, scale, and rotation invariant (PSRI) holographic associative memory. The PSRI feature space is the en-polar representation of the square magnitude of the Fourier transform, IF(fnr, fo)I2, of the objects. This representation is generated optically using a coordinate transform computer-generated hologram. Angularly multiplexed, diffuse Fourier transform holograms of the PSRI feature space are characterized as the memory unit. Distorted input objects are correlated with the hologram, and a nonlinear phase conjugate mirror, self-pumped BaTiO3, reduces cross-correlation noise and provides object discrimination. The self-pumped phase conjugate mirror is characterized, and high diffraction efficiency bleached holograms are used in the place of thermoplastic film. Applications of the memory are also presented.

Paper Details

Date Published: 1 August 1989
PDF: 5 pages
Opt. Eng. 28(8) 288849 doi: 10.1117/12.7977045
Published in: Optical Engineering Volume 28, Issue 8
Show Author Affiliations
Kenneth H. Fielding, Air Force Institute of Technology (United States)
Steven K. Rogers, Air Force Institute of Technology (United States)
Matthew Kabrisky, Air Force Institute of Technology (United States)
James P. Mills, Air Force Institute of Technology (United States)

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