Time integrating acoustooptic correlator

This paper describes an acoustooptic technique for achieving signal correlation with a time-bandwidth product of 106–108, using existing devices. One signal is used to intensity modulate a light beam that illuminates an acoustic cell. The other signal appears in the cell as a traveling wave and is Schlieren imaged onto a detector array. The detected image intensity is integrated in time, achieving the desired correlation function. Since the correlation integration is performed in time rather than space, the time-bandwidth limitations of earlier acoustooptic correlators are greatly reduced. Experimental procedures for implementation of this technique are discussed and results shown.