Development of an all-solid-state air-cooled high-power blue diode laser for metal processing

We present the design and development of an all-solid-state (fluid/refrigerant-free) 100 W scale blue-laser system and show its applications in precision copper works. We combine powerful laser-diode arrays with Peltier chips on a compact laser head to achieve stable thermal and optical performance. Good agreement between the thermal simulation of the 3D laser head and experiments validates stable thermal performance. The laser system emits 40-100 W continuous wave at λ = 452.2 ± 2.5 nm with 98% power stability and ∼24% wall-plug efficiency inside a portable enclosure. This is the first, to the best of our knowledge, all-solid-state air-cooled laser with a 100 W class output. We achieved kW/cm² intensity level on an mm-size focus with this source and demonstrated cutting, bending, and soldering copper on a battery pack. Furthermore, the copper-solder joints have nanoscale adhesion without cracks. Additionally, we unveil that 0.5-4 kW/cm² intensity laser annealing scan makes copper strips mechanically resilient to withstand extreme loading cycles without nanoscale cracks.