High-power resonantly diode-pumped CW Er3+:YAG laser

Using high-spatial and -spectral brightness laser diodes, a resonantly pumped high-power continuous-wave (CW) Er(3+): YAG laser with up to 9 W of output power could be realized. Due to the lower upconversion loss in the 0.5% Er(3+)-doped crystal, intrinsic efficiencies of up to 64.3% and an optimum outcoupling of similar to 20% were found. The output power was compared to quasi-three-level theory with good agreement. In an optimized cavity design a mode fill efficiency of similar to 95% was achieved.