All-fiber single-mode PM thulium fiber lasers using femtosecond laser written fiber Bragg gratings

Author(s): Christina Willis, Robert A. Sims,Lawrence Shah, Martin C. Richardson, CREOL, The College of Optics andPhotonics, Univ. of Central Florida (United States); Jens Thomas, Rita Becker,Christian Voigtländer, Friedrich-Schiller-Univ. Jena (Germany); AndreasTünnermann, Stefan Nolte, Friedrich-Schiller-Univ. Jena (Germany) andFraunhofer Institute for Applied Optics and Precision Engineering (Germany)
Hide Abstract Add to My Schedule

Two continuous wave Tm fiber lasers, at 1959 nm and 2055 nm respectively, wereimplemented using single mode PM silica fiber and femtosecond written fiberBragg gratings (FBG). The laser cavity consisted of a 790 nm diode spliced to ahighly reflective FBG and 2 m of active fiber. The laser output coupler waseither the Fresnel reflection from the flat cleaved output fiber facet or a lowreflectivity FBG. The best performance was achieved with the 1959 nm HR-LR FBGcavity, which yielded up to 5 W with 47.5% slope efficiency and 0.5 nm spectralwidth.