Abstract: Tungstentellurite glasses TeO₂-ZnO-Na₂O-WO₃ and tungsten-niobium-tellurite glassesTeO₂- ZnO-Na₂O-Nb₂O₅-WO₃ were investigated for the application in broadband Raman fiber amplifier. Effects of the addition of Nb₂O₅ and WO₃ on the thermal stability against crystallization and Raman spectra of tellurite glasses were discussed. The results suggest that the addition of Nb₂O₅ and WO₃ can largely improve the thermal stabilities of tellurite glasses. Moreover, the tungsten-niobium-tellurite glasses exhibits strong Raman peaks at around 862 and 921 cm^-1. The mid-high frequency Raman region of the tellurite glass co-doped by Nb₂O₅ and WO₃ expands from 550cm^-1 to 950cm^-1 with the maximum full width at half maximum (FWHM) of about 355cm-1, which indicates that the tungsten-niobium-tellurite are promising materials for broadband Raman fiber amplification.

Key words: tellurite glass, thermal stability, Raman spectrum