Efficient 1.8 μm Emission of a Novel Tm³⁺ Doped Germanate-Tellurite Glass

A new type of germanate-tellurite glass with doped Tm³⁺ ions is synthesized and its 1.8 μm emission properties have been studied for its application as a laser material. The Judd–Ofelt intensity parameters, emission cross section, absorption cross section, and gain coefficient of Tm³⁺ ions are calculated and analyzed. Germanate-tellurite glass with 1.0 mol% Tm₂O₃ possesses the highest spontaneous transition probability (423.4 s^?1) and the largest calculated emission cross section (6.91×10^?21 cm²) at 1.8 μm corresponding to the ³F₄→³H₆ transition. The good 1.8 μm emission performance suggests that this glass may become an attractive host for developing solid state lasers operating in the mid-infrared.