Development of adaptive mirror (AM) and its application to CO₂ laser processing

Material processing using CO₂ laser is one of the most highly industrialized laser technologies. Recently, there have been growing demands to improve the processing quality by flexibly control the beam properties. Development of the adaptive mirror with variable curvature function, which is one of the vital optics to realization of these demands, has been extensively pursued. We developed the AM. It maintains the same accuracy of surface figure (PV value: 1. m or below) as the conventional mirrors even when the curvature is changed, and is capable of high speed curvature control (maximum frequency: 1kHz) aiming at application to beam sawing. Further, we applied the AM to laser cutting of mild steel as an example of its practical use, and studied smoothing of the cut surface by beam sawing.