Thermal Stability and Spectral Properties of Tm 3+ -Yb 3+ CO-Doped Tellurite Glasses

Glasses of the system 75TeO 2 –20ZnO–5La 2 O 3 –0.8Tm 2 O 3 – x Yb 2 O 3 were prepared by high temperature melt cooling method. Results of differential scanning calorimetry indicate that, all glass samples have excellent thermal stability. Judd–Ofelt strength parameters, spontaneous emission probabilities, fluorescence branching rations, fluorescence radiative lifetime of Tm 3+ ions in tellurite glass were calculated. The impact of Yb 3+ concentration on the fluorescence properties of Tm 3+ ions in the S band under the pumping wavelength of 465 nm was investigated in a suggestion that, 3 H 4 radiative lifetimes will be prolonged and the performance of optical amplifier gain of Tm 3+ in tellurite glass co-doped with 0.5 mol % Yb 3+ ions will be improved.