Abstract
An Nd-doped rectangular double-clad fiber (DCF) laser pumped with a 10W fiber coupled LD is demonstrated. Furthermore, the two ends of the fiber are bundled together to achieve efficient matching with the LD. With such a configuration, about 5.4 W of the pump light is launched into the first-cladding and 2.8W laser output is obtained. A slope efficiency of 58% with respect to launched pump power has been achieved. The brightness compressibility of source to laser emission reaches to 700. It is found that the open-cavity is an optimal resonator for clad-pumped fiber lasers.
