Effects of Al2O3 on the thermal stability, glass configuration of Yb3 +-doped TeO2–K2O–ZnO–Al2O3 based tellurite laser glasses

A novel of Yb3 +-doped TeO2–K2O–ZnO–Al2O3-based tellurite glasses with both good thermal stability and high-emission cross-section was prepared by verifying Al2O3 additions. The changes in the thermal stability parameter ΔT (= Tx − Tg) and glass network configuration were investigated using differential scanning calorimeter (DSC) and Raman spectra measurements. DSC results show that the investigated tellurite glasses have favorite thermal stability for fiber drawing, and the maximum value of ΔT is up to 150 °C. Raman spectra analysis indicates that the introduction of Al2O3 changes the polyhedron structural units of Te from TeO4 to TeO3 + 1, and in a further step to TeO3 configuration. The substitution of ZnO by Al2O3 increases the glassʹs network connectivity, resulting in improvement of the glassʹs thermal stability and increase of the emission cross-section of Yb3 + ions in the glasses.