High thermal stability and intense 2.71 μm emission in Er3+-doped fluorotellurite glass modified by GaF3

In the current study, Er3+-doped fluorotellurite glasses modified by GaF3 have been developed. High thermal stability and relatively low phonon energy are confirmed by differential thermal analysis and Raman spectroscopy, respectively. Upon 980 nm excitation, intense luminescence emission around 2.71 μm from the Er3+:4I11/2 → 4I13/2 transition is observed in the glass. Based on the Judd-Ofelt theory, intensity parameters and radiative properties are determined from the absorption and emission spectra. The proposed glass possesses high thermal stability (Tg of ∼360 °C) and a large stimulated emission cross section, σem, at 2.71 μm (1.617 × 10−20 cm2). The results indicate that it can be potentially applied in high-power mid-infrared fiber lasers.