Ceramic Yb:Lu₂O₃ thin-disk laser oscillator delivering an average power exceeding 1 kW in continuous-wave operation

We report on continuous-wave (cw) laser experiments with a high-quality and large-size Yb:Lu₂O₃ polycrystalline transparent ceramic in a thin-disk laser oscillator. An output power of up to 1190 W was achieved in multimode operation with an optical efficiency of 60.3%. In fundamental-mode operation, a cw output power of 409 W was extracted with an optical efficiency of 35.6% and a beam propagation factor of M² = 1.11.