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Proceedings Paper

High accurate volume holographic correlator with 4000 parallel correlation channels
Author(s): Kai Ni; Zongyao Qu; Liangcai Cao; Ping Su; Qingsheng He; Guofan Jin
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Paper Abstract

Volume holographic correlator allows simultaneously calculate the two-dimensional inner product between the input image and each stored image. We have recently experimentally implemented in VHC 4000 parallel correlation channels with better than 98% output accuracy in a single location in a crystal. The speckle modulation is used to suppress the sidelobes of the correlation patterns, allowing more correlation spots to be contained in the output plane. A modified exposure schedule is designed to ensure the hologram in each channel with unity diffraction efficiency. In this schedule, a restricted coefficient was introduced into the original exposure schedule to solve the problem that the sensitivity and time constant of the crystal will change as a time function when in high-capacity storage. An interleaving method is proposed to improve the output accuracy. By unifying the distribution of the input and stored image patterns without changing the inner products between them, this method could eliminate the impact of correlation pattern variety on calculated inner product values. Moreover, by using this method, the maximum correlation spot size is reduced, which decreases the required minimum safe clearance between neighboring spots in the output plane, allowing more spots to be parallely detected without crosstalk. The experimental results are given and analyzed.

Paper Details

Date Published: 21 November 2007
PDF: 10 pages
Proc. SPIE 6827, Quantum Optics, Optical Data Storage, and Advanced Microlithography, 68271J (21 November 2007); doi: 10.1117/12.756670
Show Author Affiliations
Kai Ni, Tsinghua Univ. (China)
Zongyao Qu, Tsinghua Univ. (China)
Liangcai Cao, Tsinghua Univ. (China)
Ping Su, Tsinghua Univ. (China)
Qingsheng He, Tsinghua Univ. (China)
Guofan Jin, Tsinghua Univ. (China)


Published in SPIE Proceedings Vol. 6827:
Quantum Optics, Optical Data Storage, and Advanced Microlithography
Chris A. Mack; Jinfeng Kang; Jun-en Yao; Guangcan Guo; Song-hao Liu; Osamu Hirota; Guofan Jin; Kees A. Schouhamer Immink; Keiji Shono, Editor(s)

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