The growth and spectral characteristics of BaWO 4 :Tm 3+ single crystal

The BaWO4: Tm3+ single crystals of optical quality have been grown by the Czochralski technique. The lattice parameters of crystals with different doping concentrations were determined by XRD. The absorption spectra were measured at room temperature. And the optical parameters, such as transition line intensity, oscillator strength and absorption section were calculated by using Juud-Ofelt theory. The three intensity parameters were fitted to be Omega(2) = 4.04 x 10(-20) cm(2), Omega(4) = 0.509 x 10(-20) cm(2), Omega(6) = 0.134 x 10(-20) cm(2), respectively. The lifetime, branching ratio and integrated stimulated-emission cross section were obtained. Ultra-visible fluorescence was measured and analyzed. The red up-conversion luminescence with wavelengths 689 nm and 704 nm corresponding to the transition from F-3(3) to H-3(6) was observed under Ti-sapphire laser and LD laser, respectively.