Focusing of diode lasers for high beam quality in high-power applications

We have designed a diode laser system that is capable of imaging more than 50 W to a spot of 0.4 mm with a numerical aperture NA equals 0.1. The theoretical limits of the efficiency and the beam quality of the system are discussed. For applications needing higher beam quality coupling optics for a longitudinally pumped Nd:YAG laser operated in the fundamental mode are presented.