Generation of self-mode-locked resembling pulses in a fast gain-switched thulium-doped fiber laser.

We report on a generation of self-starting mode-locked resembling (MLR) pulses in an all-fiber, gain-switched Tm(3+)-doped fiber laser operating at 2 μm wavelength, which we believe to be the first demonstration of such an approach. The laser delivers 100% modulated MLR pulses within an envelope of ~30 ns gain-switched pulse at a repetition rate of 30 kHz. The maximum average output power is 0.4 W and the maximum peak-power of MLR pulses can be as high as 1.1 kW. The performance of the laser is described.