Effect of BaF2 and Y2O3 on the Raman scattering characteristics of fluorotellurite glasses

In this letter, we investigated the Raman scattering characteristics of a series of aTeO2-(90-a)BaF2-10Y2O3 (a = 85, 80, 75, 70, 65, 60, 55 mol%), bTeO2-(95-b)BaF2-5Y2O3 (b = 90, 85, 80, 75, 70, 65, 60, 55, 50 mol%) and cTeO2-(100-c)BaF2 (c = 95, 90, 85, 80, 75, 70, 65, 60 mol%) fluorotellurite glasses. With increasing the concentration of BaF2 , the peak Raman gain coefficient at 785 cm-1 increased while the Raman gain bandwidth (full spectral width at half maximum of the Raman peaks around 785 cm-1) decreased, which was attributed to the increasing proportion of non -bridge oxygen bonds in the fluorotellurite glass systems. The same results were also observed for the case of the increasing of the concentration of Y2O3. In these samples, the 50TeO2-40BaF2-10Y2O3 glass has the largest Raman gain coefficient of 29.9 x 10-13 m/W, and the 95TeO2-5BaF2 glass has the widest Raman gain bandwidth of 7.35 THz for the pumping laser at 633 nm. Furthermore, the first -order Raman Stokes light peaked at similar to 2373 nm was obtained by using fluorotellurite fiber based on the above glasses as Raman gain medium and a 2000nm picoseconds laser as pump light. Our results provide guidance for further improving the performance of Raman fiber lasers or amplifiers based on fluorotellurite fibers. (c) 2023 Optica Publishing Group under the terms of the Optica Open Access Publishing Agreement