A high power MOPA-laser based on a mode-locked thulium-doped fiber oscillator with intracavity dispersion management

We present a mode-locked thulium-doped fiber laser with intracavity group velocity dispersion (GVD) management by incorporating a low-loss single-mode germanium–silica fiber that introduces a significant amount of normal dispersion. Depending on the total GVD value, the laser generates picosecond or femtosecond pulses in the spectral band between 1930 and 1970 nm. Moreover, we demonstrate an amplifier based on an ytterbium and thulium co-doped GTWave-fiber that also acts as an external pulse compressor. We have obtained amplified pulses with durations from several picoseconds down to 200 fs and energy up to 56 nJ. (paper)