All-fiber thulium-doped mode-locked fiber laser and amplifier based on nonlinear fiber loop mirror

We report on a self-starting, anomalous dispersion mode-locked Tm-doped fiber laser based on all polarization maintaining (PM) fiber components. The oscillator, which is based on a nonlinear optical loop mirror, generates stable, linearly polarized sub-picosecond solitons at a repetition frequency of 11.78 MHz, centered at 1996.6 nm with a spectral width of 7.12 nm. Amplification of the pulses in a single-stage thulium-doped fiber amplifier resulted in an increase of the pulse energy to over 11 nJ at which soliton splitting process was demonstrated.