METHODS AND LASER PROCESSING DEVICES FOR REDUCING THE IMPACT OF THERMAL LENS EFFECTS DURING LASER MATERIAL PROCESSING
Abstract
The present invention relates to methods and laser processing devices for reducing the impact of thermal lens effects during laser material processing. In this case, an amplitude mask or phase mask (8) is inserted in the beam path of the processing laser (1) or of an additional measurement laser (13), said mask, in the focal plane in the region of the processing plane (6), generating a characteristic pattern which characteristically changes outside the focal plane. The pattern is detected by a camera (9) in the processing plane (6) during the laser processing and, on the basis of a change in the pattern, an actuating element is activated which activates optical components (5) for shifting the focus position in such a manner that a focus shift, generated by thermal lens effects, in the processing plane (6) is compensated for. Alternatively, the actuating element can also correspondingly change the distance to the processing plane (6). The methods and laser processing devices permit direct measurement of the focus shift in the processing plane and reliable compensation for said focus shift during laser material processing.
Inventors 2
- Hofmann, Jörg
- Georg König Aachen author as filed: König, Georg
Inventors are linked to an Aachen author when surname and first name match exactly one author.
Applicants
- FRAUNHOFER-GESELLSCHAFT ZUR FÖRDERUNG DER ANGEWANDTEN FORSCHUNG E. V.
- RHEINISCH WESTFÄLISCHE TECHNISCHE HOCHSCHULE AACHEN RWTH Aachen University
- Fraunhofer Ges Forschung
Cited papers 0 in the database
Non-patent literature as cited (3)
- - AUS A. GATEJ ET AL.: "Optical Modelling and Design III", 2014, SPIE, article "Methods for compensation of thermal lensing based on thermo-optical (TOP) analysis", pages: 91310F
- - O. BLOMSTER ET AL.: "Solid State Lasers XVII: Technology and Devices", 2008, SPIE, article "Optics performance at high-power levels", pages: 68712B
- - O. PÜTSCH ET AL.: "DGaO-Proceedings", 2011, article "Echtzeitfähige Laserstrahlregelung zur Kompensation thermischer Effekte"