Anisotropy of acoustooptic figure of merit for teo2 crystals. 2. anisotropic diffraction

Abstract

We present the developed method for analyzing the anisotropy of acoustooptic figure of merit (AOFM) for the case of anisotropic diffraction in optically uniaxial crystals, and we illustrate it on the example of crystalline paratellurite. We demonstrate that nine types of acoustooptic (AO) interactions can be implemented in general, six types for the isotropic interactions and three for the anisotropic ones. When the AO diffraction is collinear, the angular dependence of the AOFM is characterized by narrow peaks or dips. In the case of anisotropic diffraction, the maximum AOFMs for the paratellurite crystals are reached for the AO interactions of the type VIII with the acoustic wave QT1 propagated along the [110] direction and are polarized along [1 10]. The AOFM is equal to 929×10–15 s3/kg in this case. Nonetheless, the highest AOFM value for TeO2 crystals (1143.8×10–15 s3/kg) can be reached when linearly polarized optical eigenwaves interact isotropically with the transverse acoustic wave QT1 (see Mys O. et al, 2014. Ukr. J. Phys. Opt. 15: 132). This AO diffraction belongs to the type III. The results of our calculations agree well with the experimental data known from the literature.