High brightness laser based on Yb:YAG MOPA chain and adaptive optics system at room temperature.

We demonstrate a master oscillator power amplifier (MOPA) architecture based on Yb:YAG amplifiers and adaptive optics (AO) systems with a high power and high beam quality laser output. With two conduction cooled, dual-end-pumped Yb:YAG zigzag-slab amplifiers at room temperature, the fiber laser of 300 W was scaled to 11.9 kW. Moreover, AO system positioned downstream was utilized to correct wavefront of amplified laser. The beam quality beta at maximum output power was 2.8 times diffraction limited with closed-loop AO system. (C) 2018 Optical Society of America under the terms of the OSA Open Access Publishing Agreement