Lightweight focusing head with fast and compact adaptive mirror

Speed and accuracy in three-dimensional laser processing applications, such as cutting and welding of car bodies, is not so much limited by the available laser power or technological problems, but rather by the dynamic accuracy of the processing machines. A decisive step towards a highly dynamic processing machine has been taken with the development of a lightweight focusing head, which is presented in this article. The focusing head is designed as a modular base allowing the integration of various lightweight components. The most important of them are a focusing mirror, a position correction mirror, and an adaptive mirror. The adaptive mirror is used for controlling the axial focus position and the focus radius, respectively. A new approach for a fast and compact, yet lightweight adaptive mirror with a large range of curvature variation and good optical properties is presented.