Abstract
We have demonstrated and analyzed a high-power continuous-wave (cw) Yb:YAG laser directly pumped into the upper lasing level by a fiber-coupled laser diode with a center wavelength of 969 nm. The output power and the beam quality were compared by changing the laser-medium length and the focal length of pump-focusing lens. From a cw Yb:YAG laser with a 5-mm-long crystal and a pump-focusing lens with a focal length of 60 mm, an output power of 18.1 W has been obtained at center wavelength of 1031 nm. The M2 factors of the laser beam are 1.71 in the horizontal direction and 1.47 in the vertical direction.
