We report a novel short-length diode-pumped cw fiber laser with high output power at a wavelength of 2.8μm . The system combines continuous-wave diode pumping at 970 nm, a high doping concentration (5-mol. % ErF<sub>3</sub>) of the active fiber, and an annular geometry of the laser medium, an M-profile fiber. Output powers in excess of 1 W with a slope efficiency of 25% were obtained.
© 1999 Optical Society of America
(060.2280) Fiber optics and optical communications : Fiber design and fabrication
(060.2320) Fiber optics and optical communications : Fiber optics amplifiers and oscillators
(060.2390) Fiber optics and optical communications : Fiber optics, infrared
(060.2410) Fiber optics and optical communications : Fibers, erbium
T. Sandrock, D. Fischer, P. Glas, M. Leitner, M. Wrage, and A. Diening, "Diode-pumped 1-W Er-doped fluoride glass M-profile fiber laser emitting at 2.8 μm," Opt. Lett. 24, 1284-1286 (1999)