title: On the tunability of a narrow-linewidth Yb-fiber laser from three- to four-level lasing behaviour.
abstract: We report on a tunable multi-watt ytterbium-doped fiber laser bridging the gap from three-level lasing around 980 nm to true four-level lasing at 1100 nm. Wavelength-locking and -tuning was achieved by using an external volume-Bragg grating(VBG) as the cavity end mirror. The results are compared with detailed numerical calculations based on a spectrally resolved rate equation analysis, taking competing emission at other wavelengths into account.
authors.affiliation: Department of Applied Physics, Royal Institute of Technology, 10691 Stockholm, Sweden. pz@laserphysics.kth.se
authors.forename: Peter
authors.initials: P
authors.lastname: Zeil
authors.forename: Fredrik
authors.initials: F
authors.lastname: Laurell