10 mJ total output from a gain-switched Tm-doped fibre laser

A gain-switched cladding-pumped Tm-doped silica fibre laser operating at a wavelength of approximately 2-μm with moderate output energy is reported. When pumped with the output from a gain-switched Ti:sapphire laser, a maximum total output energy of 10.1 mJ per pump pulse is produced at a slope efficiency of 30% (with respect to launched pump energy) and, at an overall optical-to-optical efficiency of 17%. For relatively short fibre lengths, saturation of the output energy is observed with an increase in launched pump energy because of pump-induced bleaching of the pump transition. The laser has been continuously tuned using an intracavity prism over a range of 109 nm, from 1909 nm to 2018 nm.