Yb3+/Er3+ incorporated fluorotellurite glasses with varying TeO2 content for optical temperature sensing based on upconverted FIR technique

Abstract

The fluorotellurite glasses (FTGs) of TeO2–Al2O3–NaF–CaF2–YbF3–ErF3 with varying TeO2 content were prepared. Their densities, refractive indices, and thermal behaviors were characterized and analyzed with respect to the TeO2 content. The network structural nature was studied by the IR and Raman spectral techniques. The absorption and upconversion emission spectral properties of Er3+ in the FTGs were examined. Specifically, the absorption spectra were measured and used for fitting the J-O intensity parameters. The upconversion luminescence (UCL) was examined under the excitation of 980 nm laser. Furthermore, the temperature sensing performances based on the fluorescence intensity ratio (FIR) of Er3+ upconverted green emissions were evaluated for each FTG. The results confirm that the FTGs are potential materials for optical glassy temperature sensors.