Gain-switched holmium-doped fibre laser

We demonstrate the first gain-switched, singly doped, single-mode holmium-doped silicate glass fibre laser that operates at 2.106 mu m. Using a gain-switched 1.909-mu m thulium-doped fibre laser as the pump source, output pulses of energy 3.2 mu J and pulse duration of 150 ns were generated at 80 kHz and slope efficiency of 44%. Pulse stacking within the holmium-doped fibre laser resulted in significantly shorter 70 ns pulses. (C) 2009 Optical Society of America