Preparation and characterization of new fluorotellurite glasses for photonics application

Glasses based on (85 − x)TeO2–xZnF2–12PbO–3Nb2O5 (x = 0–40) system have been studied for the first time for fabricating mid-infrared optical fiber lasers. The thermal and optical properties including UV–Vis, Raman as well as FTIR spectra are reported. It is demonstrated that increasing the ZnF2 concentration to 30 mol% significantly increased the thermal stability of the glass. Adding ZnF2 also reduced the hydroxyl (OH) content of the glass resulting in lower optical absorption in the mid-infrared region, which is crucial for infrared laser applications. The glass absorption cut-off edge near 400 nm blue-shifts with increasing ZnF2 addition. Raman spectra show a depolymerization of the glass network with increasing transformation of TeO3+1 to TeO3 structures.