Tunable holmium-doped fiber laser with multiwatt operation from 2025 nm to 2200 nm

Lars G. Holmen, Peter C. Shardlow, Pranabesh Barua, Jayanta K. Sahu, Nikita Simakov, Alexander Hemming, W. Andrew Clarkson
2019 Optics Letters  
The emission band of holmium-doped silica fibers extends beyond 2200 nm, which means these lasers have potential of covering considerable parts of the atmospheric transmission window between ∼2100 nm and 2250 nm. However, efficient operation towards 2200 nm is challenging due to absorption in fused silica at the laser wavelength. Here we present a holmium-doped fiber laser specifically targeting long wavelength operation. The laser is implemented as a high-feedback wavelength selective ring
more » ... ty, and is tunable from 2025 nm to 2200 nm. A maximum slope efficiency of 58 % is obtained at 2050 nm, and a slope of 27 % at 2200 nm. A power of 5.5 W from a single aperture (8.9 W total) is demonstrated at 2200 nm. Our results represent extended coverage of the 2 µm spectral band with multiwatt-level silica fiber lasers.
doi:10.1364/ol.44.004131 fatcat:yfpdgl2ca5falczjm2ywnaq4rm