Infrared emission and energy transfer in Tm3+, Tm3+-Ho3+ and Tm3+-Yb3+-doped tellurite fibre

The infrared emission spectra and decay lifetimes of Tm3+-doped and Tm3+-Ho3+, Tm3+-Yb3+ co-doped tellurite fibres were measured using 808 nm and 978 nm diode laser pump sources in the range 1.35 mu m to 2.2 mu m. The spectra were compared with varying fibre lengths and core diameters. Tm3+-doped fibre shows strong emission at similar to 1.8 mu m and when co-doped with Ho3+, energy transfer results in strong Ho3+ fluorescence at similar to 2.0 mu m. These fibres show promise for compact mid-IR fibre laser sources. (C) 2007 Optical Society of America.