Spectroscopic investigation of Tm3+:TeO2-WO3 glass

We studied the spectroscopic characteristics of telluride glass with the host composition (0.85)TeO2-(0.15)WO3, containing 0.25 and 1.0mol% thulium oxide (Tm2O3). By analyzing the absorption spectra with the Judd-Ofelt theory, the average radiative lifetimes of 305 +/- 7.5 mu s and 1.95 +/- 0.02ms were determined for the F-3(4) and H-3(4) levels, respectively. Measured fluorescence lifetime of the 3F4 level decreased from 218 to 51 mu s for the 0.25 and 1.0 mol% Tm2O3 doped samples, respectively, indicating the effect of boosted non-radiative decay at higher doping concentrations. A similar trend was observed for the H-3(4) level, where the fluorescence lifetime decreased from 1.86ms to 350 mu s at these concentrations. The quenching of the 1460nm (F-3(4) -> H-3(4)) emission in favor of the 1800 nm (H-3(4)-> H-3(6)) emission due to cross relaxation was further evident in the. fluorescence spectra of the samples. The calculated stimulated emission cross sections (3.73 +/- 0.1 x 10(-21) cm(2) at 1460 nm and 6.57 +/- 0.07 x 10(-21) cm(2) at 1808 nm) reveal the potential importance of the Tm3+:(0.85)TeO2-(0-15)WO3 glass for applications in fiber-optic amplifiers and fiber lasers. (c) 2008 Elsevier B.V. All rights reserved.