Patent ID: 11219967

Abstract:
A processing head for a laser processing device adapted for processing a workpiece using laser radiation has: adjustable focusing optics to focus laser radiation in a focal spot having an adjustable distance from the processing head; an optical coherence tomograph to measure a distance between the processing head and the workpiece by measuring an optical interference between measuring light reflected by the workpiece and measuring light not reflected by the workpiece; a path length modulator that can change, synchronously with and dependent on a change of the focal spot distance from the processing head, an optical path length in an optical path along which measuring light propagates; a scanning device, which deflects the laser radiation in different directions; and a control device, which i) controls a focal length of the focusing optics in such a way that the focal spot is situated at a desired location on the workpiece, ii) receives, from the coherence tomograph, information representing the distance between the processing head and the workpiece, and iii) uses information received from the coherence tomograph for a continuous correction of a positioning of the focal spot on the workpiece.