Effects of Nb_2O_5/WO_3 Codoping on Thermal Stability and Raman Spectral Properties of Tellurite Glasses

Tungsten-tellurite glasses TeO2-ZnO-Na2O-WO3 and tungsten-niobium-tellurite glasses TeO2-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.