Efficient optical enhancement of acousto-optic diffraction using optimized overlap of coupled waves

We describe a technique by which the diffraction efficiency of an acousto-optic beam deflector may be substantially increased under high-power laser illumination. In earlier research we showed that the diffraction process is intrinsically associated with an intensity-dependent modification of the diffraction efficiency of an acousto-optic device. Here we show that this diffraction efficiency may be enhanced most effectively by distributing the optical intensity over the acousto-optic device in a manner that maximizes the overlap with the acoustic wave in the medium. In particular, we demonstrate increases in diffraction efficiency of greater than 80% in a TeO(2) device-an improvement of roughly an order of magnitude over earlier results in which this overlap technique was not used.