Abstract

Cross talk is observed in a double-phase conjugator and utilized to construct a moving object correlator. Separate objects are placed in each arm of a double-phase bridge phase conjugator by using a strontium barium niobate cerium doped crystal. During the transient time of grating or bridge formation, cross talk is observed in each arm of the double-phase phase conjugator. After a time corresponding to the characteristic photorefractive response time of the crystal, the cross talk is observed to disappear. If one of the objects in either arms is suddenly moved, however, a signal representing the correlation between the object in each arm can be observed in the correlation plane of the other arm. Consequently, as long as the object in one arm of the double-phase phase conjugator is moving, the signal representing the correlation between the two objects can be observed in the others arm's correlation plane. If the moving object becomes stationary for a time longer than the photorefractive response time, however, the correlation signal disappears. In this way, only the correlation signal between objects moving in one arm and stationary reference objects in the second arm are observed.

© 1992 Optical Society of America