Broadband 2 μm emission characteristics and energy transfer mechanism of Ho3+ doped silicate-germanate glass sensitized by Tm3+ ions

The Tm3+/Ho3+ co-doped silicate-germanate glasses with good thermal properties were synthesized by high temperature melting method. 2.0 μm emissions with broad effective half-width (231.5 nm) were successfully obtained in present Tm3+/Ho3+ co-doped glasses without obvious quenching upon excitation of a commercial 808 nm laser diode. To further understand 2 μm fluorescence behaviors of the prepared glasses, energy transfer mechanism, efficiency, rate and microparameters from different levels of Tm3+ to Ho3+ ions have been obtained and discussed. In short, the Tm3+/Ho3+ co-doped silicate-germanate glass with excellent spectroscopic properties might be an attractive host material for 2 μm broadband solid laser.