Generation of 25-ns pulses with a peak power of over 10 kW from a gain-switched, 2-mm Tm-doped fibre laser and amplifier system

We report on an all-fibre, gain-switched, Tm³⁺-doped silica fibre laser and amplifier system generating a train of pulses at a wavelength of 1994.4 nm. When operating at a pulse repetition frequency f = 100 kHz, it delivered the maximum average power as high as 9.03 W with a slope efficiency of 36.4%. At f = 26 kHz, stable 25-ns pulses with an energy of 0.28 mJ corresponding to a peak power of 10.5 kW were obtained. The performance of the laser system is described.