New Acousto-Optic Regime of Interaction in Media Possessing Strong Elastic Anisotropy

Abstract

We present results on theoretical and rst experimental investigation of a new regime of acousto-optic interaction existing in acoustically anisotropic medium. We de ned the new regime as semi-collinear or mixed interaction since it combined properties of the traditional non-collinear di raction and the pure collinear interaction. The peculiar phenomenon was registered in the tellurium dioxide crystal due to the extremely strong elastic anisotropy of the material. Application of a speci c cut of the crystal provided observation of the e ect in the middle infrared at the optical wavelength 3.39 μm and at the acoustic frequencies limited to 300 MHz. The observed interaction was characterized by a non-collinear propagation of incident light with respect to acoustic energy ow and simultaneously a collinear propagation of di racted radiation along the acoustic energy ow. A brief theoretical analysis of the interaction based on wave vector diagrams and two-dimensional coupled wave equations is included in the presentation. Finally, we describe in the paper, the setup and basic details of the carried out acousto-optic experiment.