Fanning Laser Light Application to the Characterization of Bi<sub>12</sub>TiO<sub>20</sub> and Bi<sub>12</sub>SiO<sub>20</sub> Crystals

Abstract

Bi 12 SiO 20 and Bi 12 TiO 20 crystals were grown using the melting technique. The crystals were characterized by DTA, X-ray diffraction, and chemical etching. The fanning effect is known as a self-scattering process in which a single laser light beam self-generates scattering in an asymmetrical way. The intensity distribution of fanning light in the far field measured under an applied electric field, normalized to the intensity measured without a field represents the two-wave mixing gain factory γ. For the experiments an argon laser with λ=515nm and the maximum power of 0.5 W was used and the scattered intensity was recorded. The factor γ(θ,φ) for a set of samples was calculated using the intensity distribution in the far field, recorded with a CCD camera. The values of γ(θ,φ) were correlated with the optical inhomogeneity of the crystals.