Patent ID: 8653406
Filing Date: 2014-02-18
Classification: B23K

Abstract:
1. A process for processing and/or joining work pieces by means of laser radiation, with an effective power laser and a pilot target laser that emit an effective laser beam and a pilot laser beam of different wavelengths, using laser optics to image the laser beams of the effective laser beam and of the pilot laser beam on the work pieces, the laser optics having randomly selectable beam patterns that are superimposed and identical in terms of position and form, wherein the form of the beam patterns is determined with at least one diffractive optical element (DOE) that is integrated in the laser optics, and a beam expansions system either with one diffractive optical element being used for the two laser beams and, after the diffractive optical element, the smaller beam cross-section of the pilot laser beam being adjusted to match the larger beam cross-section of the effective laser beam, or with two differently designed diffractive optical elements being used, with one diffractive optical element being associated with each of the two laser beams, with said diffractive optical elements matching the beam cross-section of the pilot laser beam and the beam cross-section of the effective laser beam so that the size of the beam patterns on the work pieces is approximately the same, wherein the beam expansion system includes beam deflection elements, and the processing further comprising using the beam deflection elements to separate the pilot laser beam from the effective laser beam for part of a path length between the diffractive optical element and the work pieces, and in that the cross-section of the pilot laser beam is enlarged after the separation.