Single-frequency narrow linewidth 2 μm fiber laser

摘要: A compact single frequency, single-mode 2 μm fiber laser with narrow linewidth, <100 kHz and preferably kHz, is formed a low phonon energy glass doped triply ionized rare-earth thulium and/or holmium oxide gratings in sections of passive silica fused thereto. Formation the both facilitates splicing to other optical components reduces noise thus improving linewidth. An increased doping concentration 0.5 15 wt. % for thulium, or mixtures thereof produces adequate gain, hence output power levels lengths less than 5 cm 3 enable single-frequency operation.