High-speed pattern recognition by using stimulated echoes

Abstract
We present experimental results demonstrating the use of stimulated echoes for high-speed pattern recognition. One data image and two reference images (spatially encoded laser pulses) were stored and processed in a Pr3+:LaF3 crystal by focusing the pulses sequentially into the storage material. The processed information was later retrieved by a read pulse, generating two temporally separated echo images that are the spatial correlations between the data and reference images. Identification of the data image was accomplished by finding the echo image that showed the highest spatial correlation with the data image. The present processing speed is 30 ns per correlation operation.