Spectroscopic investigations of OH − influence on near-infrared fluorescence quenching of Yb 3+/Tm 3+ co-doped sodium-metaphosphate glasses

Abstract

Energy transfer processes were studied in two sets of Yb 3+ and Tm 3+ co-doped sodium-metaphosphate glasses, prepared in air and nitrogen atmospheres. Using Förster, Dexter, and Miyakawa theoretical models, the energy transfer parameters were calculated. The main ion–ion energy transfer processes analyzed were energy migration among Yb 3+ ions, cross-relaxations between Yb 3+ and Tm 3+ ions, and interactions with OH − radicals. The results indicated that Yb→Tm energy transfer favors 1.8 μm emissions, and there is no evidence of concentration quenching up to 2% Tm 2O 3 doping. As expected, samples prepared in nitrogen atmosphere present higher fluorescence quantum efficiency than those prepared in air, and this feature is specially noted in the near-infrared region, where the interaction with the OH − radicals is more pronounced.