Stable 10 ns, kilowatt peak-power pulse generation from a gain-switched Tm-doped fiber laser

We report what we believe to be the first demonstration of stable short pulse (10 ns) generation from a gain-switched Tm-doped fiber laser in the 2 microm spectral region. A modulated 1.55 microm pump laser was used for fast gain switching to regulate the conventionally chaotic spiking in the gain-switched fiber laser. From a 6.3 microm core all-fiber oscillator, over a kilowatt of peak power was obtained at the slope efficiency of 50% and freely varying repetition rate up to 500 kHz.