Preparation and spectral characteristics of Tm 3+ /Ho 3+ co-doped TeO 2 -B 2 O 3 -BaO glass.

TeO-B 2 O 3 -BaO glasses with different compositions were prepared by the conventional melt-quenching technique. The spectral properties of Tm 3+ /Ho 3+ co-doped TeO-B 2 O 3 -BaO glasses with different doping concentrations were studied. In order to analyze the spectroscopic properties in detail, the Judd-Ofelt intensity parameters, spontaneous radiative probabilities, branching ratios, absorption and emission cross-sections, and gain coefficient spectra were calculated using Judd-Ofelt and McCumber theory based on the absorption and emission spectra. Meanwhile, the optimal doping concentration was determined as Tm 2 O 3 : 1.0 mol% and Ho 2 O 3 : 1.0 mol%. The results show that Tm 3+ /Ho 3+ co-doped TeO-B 2 O 3 -BaO glass is an ideal mid-infrared laser gain medium.