High-power diode lasers are a focal point for laser technology. In recent years, they have developed from an attractive but costly solution for niche markets into a key laser product with broad applications such as the pumping of solid-state lasers and direct use in the field of medicine. The driving factors for this development have been the constantly increasing output power and increased reliability and lifetime. The output power per bar for commercial high-power diode lasers rose by more than a factor of five over the last 10 years. If we look at research and development results, there seems to be no frontier in sight: The peak laboratory values are even higher, by nearly another factor of five -- the highest reported output power per bar being nearly 270 W…