Abstract

A real-time optical cross correlator of very long digital or analog data streams and capable of operating in excess of 40 million samples per second is described. The overall system architecture relies on the implementation of the overlap-and-add algorithm. The algorithm has been appropriately modified to implement the cross correlation of two long signals by first computing the cross correlation of many shorter ones. The optical system utilizes a cw laser source, an acousto-optic cell, a liquid crystal display and a multichannel parallel photodiode array to implement the short correlations. A digital system is used to form the final correlation output. Preliminary results are described.

© 1992 Optical Society of America