CW-lasing and amplification in Tm(3+)-doped photonic crystal fiber rod

We report lasing and amplification in a rod type thulium-doped photonic crystal fiber with 80 μm core diameter. The rod is pumped with a 793 nm laser diode and produces more than 20 W output power at a beam quality M(2)<1.3. The laser/amplifier has a slope efficiency of 27.8%/20.1% relative to absorbed pump power with a lasing threshold at 28.6 W. The output wavelength in the lasing configuration can be tuned over 180 nm from 1810-1990 nm.