Optical transitions of Tm3+ in oxyfluoride glasses and compositional and thermal effect on upconversion luminescence of Tm3+/Yb3+-codoped oxyfluoride glasses.

Abstract Optical properties of Tm 3+ -doped SiO 2 –BaF 2 –ZnF 2 glasses have been investigated on the basis of the Judd–Ofelt theory. Judd–Ofelt intensity parameters, radiative transition probabilities, fluorescence branching ratios and radiative lifetimes have been calculated for different glass compositions. Upconversion emissions were observed in Tm 3+ /Yb 3+ -codoped SiO 2 –BaF 2 –ZnF 2 glasses under 980 nm excitation. The effects of composition, concentration of the doping ions, temperature, and excitation pump power on the upconversion emissions were also systematically studied.