Kilowatt level high-power thulium-doped fiber laser

In this paper, a high power Tm3+-doped fiber laser (TDFL) based on a monolithic master oscillator power amplifier (MOPA) system with the center wavelength is 1940 nm is demonstrated. The maximum laser power was measured to be 909 W with a slope efficiency of 50.1% at the 793 nm pump power of 1816 W. Power stability of the laser output over 60 min is measured to be ~0.14% .Output power is pump-limited without the onset of parasitic oscillation or amplified spontaneous emission (ASE) even at the maximum power, showing further power scaling should be possible with increase the pump power.