DETECTION OF BLEUSTEIN-GULYAEV SURFACE-WAVES PROPAGATING ON HEXAGONALCRYSTALS USING ACOUSTOOPTIC INTERACTION

Bleustein-Gulyaev (BG) waves retain the main advantages of surface aco ustic waves (SAW), while being less sensitive to surface stresses and contamination. Our aim here is to study the acousto-optic detection of this kind of SAW using a laser probe. The interaction of BG waves wit h light propagating in the SAW sagittal plane is investigated theoreti cally for zinc oxide (ZnO) and cadmium sulphide (CdS) crystals with he xagonal symmetry (6 mm). The diffraction of the reflected and transmit ted beam is studied versus the angle between the light wavevector and the normal to the SAW supporting plate (the depth direction along whic h the SAW attenuates). Some experimental results are also reported and compared with the above theory.