Apparatus and method for monitoring a machining process for material processing by means of an optical reference beam to compensate for dispersion effects

摘要

The invention relates to a device (10) for monitoring a machining beam (18) for material processing by means of an optical measuring beam (42), wherein the machining beam (18) can be projected and focused onto a workpiece (W) via a processing beam optics (12), wherein the Machining beam optics (12) having a plurality of optical elements, wherein the machining beam (18) after exiting the processing beam optics (12) to hitting the workpiece (W) travels a distance. The device comprises an optical coherence tomograph (14) with an optical measuring arm (M) in which the measuring beam (42) projects from the light source (44) via the measuring beam optics (58) and the processing beam optics (12) onto the workpiece (W) , is at least partially reflected by this and for evaluation to the analysis device (S) is performed, and an optical reference arm (R) for monitoring the processing beam (18) by means of the optical measuring beam (42) the measuring arm (M) optically simulated and a reference beam (100), wherein the reference arm (R) or the measuring arm (M) further comprises a dispersion compensating device (82) to compensate for optical dispersion effects in the processing beam optics (12), wherein the dispersion compensation device (82) is adapted to optical Dispersion effects resulting from a mismatch of the of the measuring beam (42) and the reference beam (100) in the Messs Trahloptik (58) and in the processing beam optics (12) traversed optical material of the measuring arm (M) and of the reference beam (100) traversed optical material of the reference arm (R) result.