Tm-based fiber-laser system with more than 200 MW peak power

Tm-based fiber-laser systems are an attractive concept for the development of high-performance laser sources in the spectral region around 2 µm wavelength. Here we present a system delivering a pulse-peak power higher than 200 MW in combination with 24 W average power and 120 ?J pulse energy. Key components enabling this performance level are a Tm-doped large-pitch fiber with a mode-field diameter of 65 µm, highly efficient dielectric gratings, and a Tm-based fiber oscillator operating in the stretched-pulse regime.