Linear and non-linear optical properties of antimony thiourea bromide crystals

Single crystals of antimony thiourea bromide with molecular formula Sb[CS(NH2)(2)](2)Br-3 (ATB) have been grown in gels at ambient temperature. Linear optical properties of this material such as refractive indices, birefringence and absorption characteristics were measured in the wavelength range 200nm - 1400nm. No dispersion of the birefringence was observed within the experimental accuracy. Optical second harmonic generation (SHG) of Nd:YAG laser (lambda= 1.064mum) has been observed for ATB crystal. In order to reveal the origin of non-linear optical property crystal structure of ATB has been determined. The nonlinear optical property in ATB is due to the polar axis of the packing.