Acousto-Optics and Applications Acousto-Optic Diffraction by Shear Horizontal Surface Acoustic Waves in 36 ◦ Rotated

We have investigated the acousto-optic diffraction by shear horizontal surface acoustic waves in 36 ◦ rotated Y-cut X-propagation lithium tantalate (LiTaO3) crystals. The measurements were performed at the optical wave-length 633 nm of HeNe laser and acoustic wavelengths of 5060 µm. The anisotropic diffraction with the light polarization rotation in the transmission mode was observed. The measured and calculated values of the light incidence angle corresponding to the strongest diffraction differed significantly. A narrow strip of a thin metal film deposited on the crystal surface drastically affected the light diffraction. We attribute these effects to the con-version processes between the shear horizontal leaky surface acoustic wave and shear horizontal surface skimming bulk wave