Direct pattern recognition of a motion picture by hole-burning holography of Eu(3+):Y(2)SiO(5)

We propose and demonstrate a novel technique for direct pattern recognition of motion pictures based on frequency- and spatial-domain holography using a cryogenic Eu(3+):Y(2)SiO(5) crystal. The fast hole-burning speed of the crystal allows a moving image to be continuously recorded in it by a frequency-scanned laser. Using Fourier transform holography permitted direct pattern recognition of a 25-s movie stored in the crystal to be realized. The correlation spot continuously followed the moving object with the same time resolution (10 ms) as the reproduced movie.