The effect of high temperature heat treatment on the directional homogeneity of LiNbO3 crystal studied through transmission ellipsometry

Abstract

Pure and doped lithium niobate (LiNbO3) crystals heat treated at temperatures up to 1000°C under reduced/oxidized atmospheres were studied through normal incidence transmission ellipsometry in which a laser with a wavelength of 632.8 nm was employed. The differences in refractive indices between two orthogonal directions were calculated. Results show that the birefringence varies depending on thermal history of the samples.