35 kW peak power picosecond pulsed thulium-doped fibre amplifier system seeded by a gain-switched laser diode at 2 μm

High power fibre laser sources in the 2 μm wavelength region with picosecond-scale pulse durations have attractive applications such as materials processing, eye-safe radar and nonlinear frequency conversion to mid-infrared wavelengths. Current implementations are typically based on the amplification of picosecond pulses obtained from a mode-locked oscillator, and pulse energies of several hundred nano-Joule and peak powers of the order of 10 kW have been achieved [1, 2].