Acousto-optic interaction in TeO2 and LiNbO3 devices with surface generation of bulk acoustic waves

In this paper, a theoretical and experimental study is presented related to light interaction with bulk acoustic waves generated from a surface of piezoelectric LiNbO3 and TeO2 crystals. A paratellurite acousto-optic cell was designed and developed on base of conversion of acoustic modes during a reflection from a tilted surface in the cell. An intrinsic shear acoustic wave was excited along [001] axis in the material by means of two metal electrodes deposited on the (001) crystal facet. After the reflection, the shear wave propagated along [001] axis and then it was converted into the [110] mode with the velocity 617 m/s. A prototype acousto-optic device based on XY-cut of LiNbO3 is also described in the paper. Experimental investigation of the devices proved that the diffraction efficiency about 1% was obtained in the paratellurite crystal and also about 2% in the lithium niobate at 1.0 Watt of driving electric power. In this way, a possibility has been demonstrated of a non-traditional acoustic wave generation in acousto-optic devices providing light beam control.