Transforming Acoustic Waves to Create Acousto-optic Devices

This study focuses on the issue of acoustic mode conversion at the interface between a crystal and vacuum. The significance of this problem stems from the application of this excitation method for generating a shear elastic wave in wide aperture acousto-optical filters. Utilizing the fundamental laws of reflection for arbitrary media, this research examines a specific case of transforming a longitudinal elastic wave into a slow shear wave at the boundary of a paratellurite crystal, which is commonly employed in filter design. The outcomes of a numerical assessment of the amplitude and energy reflection coefficients for all acoustic modes are reported.