Observation of high-gain nonlinear acousto-optic amplification

We describe a procedure by which the optical and acoustic waves present in an acousto-optic beam deflector are strongly amplified through nonlinear optical pumping. This amplification is manifested as an increase in the diffraction efficiency of an acousto-optic beam deflector. In particular, we describe the design and experimental test of a prototype TeO(2) device in which this diffraction efficiency was increased by more than 2 orders of magnitude under pulsed laser illumination. This high degree of amplification results from an acoustic gain mechanism that counteracts the usual attenuation of sound waves propagating in an acousto-optic medium. We discuss possible applications of this gain mechanism in a new class of nonlinear acousto-optic device.