Birefringence induced by uniaxial stress in cadmium telluride single crystals

The birefringence induced by uniaxial stress in cadmium telluride single crystals was investigated. Static uniaxial compression was applied along the (100), (110), (111) and (112) directions. It was found that n/sub ///-n perpendicular to changes sign near the absorption edge. The position of the inversion point depends on the direction of stress and the direction of light. The components of the piezooptic tensor in the region from 2 mu m to the absorption edge were calculated. The spectral dependence of piezobirefringence is explained using the Kramers-Kronig relation and taking into account transitions at the centre of the Brillouin zone and at the point Lambda . It was shown that the splitting of the degenerate bands and the changes of the matrix element with stress should be taken into account to explain the dispersion of piezobirefringence.