Pure phase correlator with photorefractive filter memory
We report on the investigation of a new compact configuration of an inverted VanderLugt-type correlator system. The phase of the Fourier transform of the image to be recognized is displayed on a phase-modulating electrically addressed spatial light modulator. This phase display is compared with the...
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Published in | Optics letters Vol. 22; no. 2; p. 87 |
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Main Authors | , , , |
Format | Journal Article |
Language | English |
Published |
United States
15.01.1997
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Online Access | Get more information |
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Summary: | We report on the investigation of a new compact configuration of an inverted VanderLugt-type correlator system. The phase of the Fourier transform of the image to be recognized is displayed on a phase-modulating electrically addressed spatial light modulator. This phase display is compared with the phase of the Fourier transforms of a reference library recorded in a photorefractive LiNbO(3) crystal. Angular hologram multiplexing permits fast data access, and the use of the conjugated replica of the stored templates leads to an elimination of phase distortions introduced by the optical system. With such a configuration, the correlator is fully shift invariant in spite of the photorefractive crystal thickness and has good discrimination with sharp correlation peaks. |
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ISSN: | 0146-9592 |
DOI: | 10.1364/OL.22.000087 |