In order to obtain broadband and high Raman gain coefficient in the tellurite glass, a detailed study of the effects of WO 3 , MoO 3 , and P 2 O 5 in TeO 2-ZnO-Na 2 O-Nb 2 O 5 (TZNN) glass system on the thermal stabilities and Raman spectroscopic was performed. It was found that both WO 3 and MoO 3 improved the glass thermal stability and enhanced the bandwidth significantly. Higher Raman gain coefficients and broader bandwidth were realized in the MoO 3 modified glasses than those of WO 3 added glass. The tellurite glass containing 15 mol. % MoO 3 exhibits the bandwidth 1.7 times larger than the silica glass and the Raman gain coefficient is as high as 38 times that of the silica glass. Moreover, with the addition of P 2 O 5 in TeO 2-ZnO-Na 2 O-Nb 2 O 5-WO 3 (TZNNW) and TeO 2-ZnO-Na 2 O-Nb 2 O 5-MoO 3 (TZNNM) glass systems, the thermal stabilities can further be improved. On the other hand, the Raman bandwidth can further be broadened, especially in the TZNNMP glass system. The tellurite glass containing 15 mol. % MoO 3 and 15 mol. % P 2 O 5 shows the bandwidth 1.9 times larger than the silica glass and maintains high Raman gain coefficient which is as high as 37 times that of the silica glass, indicating this glass is a promising candidate as new gain media for broadband Raman fiber amplifier. V

Tungstenª²tellurite 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.