Natural frequencies of acousto-optic TeO2 crystals

The optical measurements were carried out for the incident light of E (perpendicular to) C-4 and E parallel to C-4, (C-4 is the optical axis of crystals) in the 50 - 50000 cm(-1) spectral range. By the Kramers -Kronig relation the calculations are made of dispersions of the real and imaginary parts of dielectric penetration, as well as of the factors of refraction and absorption, and natural frequencies are determined. Frequencies of active phonons in the IR spectrum are determined. The IR reflection spectra (E parallel to C-4) contain 4 intensive absorption bands x(v) and 8 bands in spectra of E (perpendicular to) C-4 which were interpreted in terms of theoretical group analysis of D-4 point symmetry group of TeO2 crystals. The natural frequencies of the TeO2 were determined.