Crystal structure and optical activity of La3Ga5SiO14 crystals

Abstract

Using a laser polarimeter (635 nm), we have obtained a spatial distribution map of optical rotatory power (OR) on a z-cut sample of langasite crystals La3Ga5SiO14 with the transverse dimensions of 317 mm 2 and the thickness of 0.945 mm. A possible impact of linear optical birefringence on the measured OR is clarified. Basing on polarizability theory of the optical activity effect, the OR is calculated as a function of disordering structure parameters of the material under investigation. It is shown that the structural disorder prevails in the spatial changes of OR along the optic axis.