Enhanced broadband 1.8 μm emission in Bi/Tm3+ co-doped fluorogermanate glasses

Enhanced broadband 1.8 mu m emission has been demonstrated in Bi/Tm3+ co-doped fluorogermanate glasses under a selectable pumping scheme. Detailed studies based on structure analysis, absorption spectra, excitation and emission spectra, and dynamic luminescence decay curves indicate that the enhanced broadband 1.8 mu m luminescence originates from extremely efficient energy transfer process from Bi to Tm3+. Furthermore, the detailed energy transfer mechanism between Bi and Tm3+ is rationally analyzed. This novel pumping scheme and sensitizing mechanism of Bi/Tm3+ co-doping could provide the experimental basis for similar to 2.0 mu m laser flexibly pumped by visible lasers, optical parametric oscillators, commercial 808 and 980 nm laser diodes. (C) 2015 Optical Society of America