We report lasing and amplification in a rod type thulium-doped photonic crystal fiber with 80 am core diameter. The rod is pumped with a 793 nm laser diode and produces more than 20 W output power at a beam quality M2 <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.
Gaida, C., Kadwani, P., Leick, L., Broeng, J., Shah, L., & Richardson, M. (2012). CW-lasing and amplification in Tm3+-doped photonic crystal fiber rod. Optics Letters, 37(21), 4513-4515. https://doi.org/10.1364/OL.37.004513