High-frame-rate joint Fourier-transform correlator based on Sn(2)P(2)S(6) crystal.

We present a joint Fourier-transform correlator working at a 10-kHz repetition rate. It is based on a photorefractive Sn(2)P(2)S(6) crystal operated in the pulsed direct band-to-band photoexcitation regime at a wavelength of 532 nm and a pulse length of 50 ns. The intersection of two plane waves with a total pulse fluence of 100muJ/cm(2) results in a buildup of thin dynamic holograms to a typical diffraction efficiency of 10(-4) in a time of ~1mus and decay again in less than 10mus . The correlator was tested by a fast image sequence generated by the pulsed readout of a holographic memory system. Successful correlation at a rate of 10 kHz has already been achieved for a pulse energy of only 200 nJ in the template images.

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