Yb:YAG power oscillator with high brightness and linear polarization

A diode-pumped Yb:YAG laser with a novel end-pumped zigzag slab architecture has been developed. This architecture provides uniform transverse pump profiles, conduction cooling of the laser crystal, mechanical robustness, and ready scalability to higher powers. At room temperature the laser emits 415 W of cw power with 30% optical conversion efficiency. An image-inverting stable resonator permits a high-brightness output of 252 W with linear polarization and an average M(2) beam quality of 1.45. Q-switched pulse energies of as much as 20 mJ and average Q-switched powers of as much as 150 W were obtained while M(2) was maintained at <1.5.