Ring profile with new center flat axicon lens

We have developed a "Center Flat Axicon Lens" for laser processing. This Center Flat Axicon Lens combines a condenser lens and an axicon lens into single lens. This axicon lens has a unique equation that uses a large negative value conic constant and a quadratic term that is not typically used with aspheric lenses. In this equation, conic constant controls the ring size, and the quadratic term controls the focal length. The smaller the conic constant, the smaller the ring size. Additionally, we developed a tilt correction mechanism and a detachable alignment profiler to make a balanced Ring beam and correct the biased laser from the delivery fiber. In this detachable alignment profiler, we used V-shape transparent type beam splitter to attenuate the laser to correct the transmittance variance depending on incident angle. We used proprietary software for astigmatism correction. Using our software correction, we were able to get a balanced Ring. After that we modified a Center Flat Axicon Lens to Center/Ring lens; the outer part of this lens is Center Flat Axicon Lens and inner part is normal aspherical condenser lens. Then we performed copper welding. Compared with Gaussian profile this Center/Ring profile resulted in decreased spatters and penetration stability was improved.