We report on an efficient diode-end-pumped polycrystalline Yb:Y <sub>2</sub>O<sub>3</sub> ceramic laser. Continuous-wave output power of 4.2 W at 1078 nm was obtained under pump power of 19.5 W. The corresponding slope efficiency was 29%. The beam quality factor (<i>M</i><sup>2</sup>) at full pump power was measured to be 1.63. The threshold wavelengths of the laser at various output couplings were also investigated. It was found that the threshold wavelengths shifted ~5 nm when the reflectivity of the output coupler changed from 90% to 99.9%, as caused by the strong reabsorption effect in the ceramic sample.
© 2004 Optical Society of America
J. Kong, D. Y. Tang, J. Lu, K. Ueda, H. Yagi, and T. Yanagitani, "Diode-end-pumped 4.2-W continuous-wave Yb:Y2O3 ceramic laser," Opt. Lett. 29, 1212-1214 (2004)