A Yb3+/Tm3+/Ho3+ triply-doped tellurite fibre laser

Continuous wave laser emission at 2.1 microm from a Yb(3+)/Tm(3+)/Ho(3+) triply-doped tellurite fibre laser is reported. The fibre was pumped at 1.1 microm by a Yb(3+)-doped double-clad silica fibre laser. For a 17 cm fibre length and 99%???60% reflectance cavity, the threshold was 15 mW and the slope efficiency was 25%. A maximum output of 60 mW was observed for a launched pump power of 270 mW, corresponding to 22% optical-to-optical efficiency.