Real-time Incoherent Optical Pattern Recognition with Photorefractive Crystals

Abstract

Incoherent optical pattern recognition has been demonstrated with a simple setup using photorefractive BaTiO3 crystals. The input patterns to be identified can be transmitted into the system with completely incoherent (both temporal and spatial) light. The setup does not require prefabricated filters for its operation and is thus a real-time system. The working principles of the system involve the photorefractive beam fanning effect and degenerate four-wave mixing.

<title>Training of self-pumped phase-conjugate mirrors based on photorefractive nonlinearity</title>

“…In our opinion, the approach used in the paper can be also applied for solving pattern recognition problems [25,26], in the development of optical correlators [27] and elements of the associative memory [28][29][30] based on SPPC mirrors.…”

“…The concept of such a training is closely related to the pattern recognition problems [25,26], the development of optical correlators [27] and elements of the associative memory [28][29][30] based on SPPC mirrors. In one of the variants of such devices considered earlier, the authors [30] studied the possibility of simultaneous holographic writing of several timeseparated input images in a PRC.…”