Use of angular plane-wave spectra in the analysis of three-dimensional weak acousto-optic interaction

We present a method for conveniently calculating three-dimensional weak acousto-optic scattering. In our method the conventional cumbersome volume-scattering triple-integral technique is replaced by an equivalent single-integral formalism, framed in terms of the angular plane-wave spectra of sound, incident light, and scattered light. Our technique is suitable when paraxial conditions apply and is correct to second-order terms in propagation angles. The interaction of spatially separated Gaussian optical and acoustic beams is described as an example.