New generation of high power reflective focusing optics (HPRFO)

As the high power laser market continues to grow, so does the need for robust optical solutions that can withstand the inherently harsh environment of laser welding. EWI continues to push the design envelope for high power optics that are capable of withstanding 20 kW or more of laser power for extended periods of time. A second version of EWI’s high power reflective focusing optics, referred to as HPRFO2, incorporates a patented aero window for internal protection of critical components, improved process effluent protection, and a revised beam delivery path. Long focal lengths separate the critical optics from the harsh welding environment without compromising the focal spot size. The previously published results of version one of the HPRFO exhibited minimal focal shift, unmatched by commercially available optics. In this work a production hardened version was designed and tested. Key attributes, which proved successful in version one of the HPRFO, were incorporated in the new design along with changes resulting from lessons learned. Shallower fold angles (compared to original HPRFO) for the asymmetric aspheric mirrors, adaptable effluent management solutions and better thermal management were included in the new design. Initial testing of the HPRFO2 demonstrated promising results and robustness unrivaled by commercially available optics.