We describe erbium-ytterbium co-doped fiber lasers in different free-running and tunable configurations. The lasers were cladding-pumped by high-power multimode diode sources. We compare pumping at 915 and 980 nm. With a free-running laser, we obtained slope efficiencies of up to 50% with 915-nm pumping and 38% with 980-nm pumping, with respect to absorbed pump power. We reached a double-ended output power of 16.8 W from the free-running laser. Thanks to a high rare-earth concentration and a small inner cladding area (possible with the high-brightness pump sources we used), the operating pump absorption of the fiber reached 8 dB/m. With such high absorption, short fibers with high nonlinear thresholds are possible even with cladding pumping. The tunable fiber laser had a tuning range from 1533 to 1600 nm and emitted 6.7 W of output power at 1550 nm in a high-brightness, single-polarization, narrow linewidth beam.
Nilsson, J., Alam, S. U., Alvarez-Chavez, J. A., Turner, P. W., Clarkson, W. A., & Grudinin, A. B. (2003). High-power and tunable operation of erbium-ytterbium co-doped cladding-pumped fiber lasers. IEEE Journal of Quantum Electronics, 987-994. https://doi.org/10.1109/JQE.2003.814373