| Verfahren zur Materialbearbeitung mit Laserstrahlung sowie Vorrichtung zur Durchfuehrung des Verfahrens (2007) | |||||||
Abstract | |||||||
| DE 102007024700 A1 UPAB: 20081217 NOVELTY - Focusing is effected to form a beam waist. Fractions of the beam (7) are deflected to diverge from the axis (4) at, ahead of and/or after the beam waist, hence being directed away from the beam axis. The fractions and their angles of divergence exceed those resulting from imaging errors arising inevitably with standard optics and which can be taken into account. DETAILED DESCRIPTION - The increased angles of divergence are used to reduce the angles of incidence on the surface of interaction (8), in this way increasing surface absorption and reducing variation of absorption with fluctuations in angle of incidence. Such divergences are produced internally or externally to the laser, using one or more beam-forming optics. They are achieved in one or more ways, as follows. The beam-forming optic has increased aberration. It has correspondingly-increased positive- or negative spherical aberrations and/or chromatic aberrations. Diffractive and/or diffusive optical elements are employed. The optical elements are solid, liquid and/or gaseous materials or media, with transmissive and/or refractive properties. Concave and convex optical interfaces achieve the aberration. The optic causing aberration, simultaneously collimates and/or focuses the beam. At least one aspherical surface is used. The optic is an axicon (conical lens) or Fresnel optic. Aberration is formed by one or more optics having a refractive index varying laterally and/or axially. The optic is adaptive, permitting the degree of aberration and/or the lateral and/or axial distribution of aberration to be adjusted. A control unit adjusts and matches working parameters during operation. These include: type of material (1), material thickness, operating velocity and/or laser power. The optic adjusts the maximum angle of divergence to form spatial power density distributions. These are ring- or top-hat distributions at the surface of interaction. AN INDEPENDENT CLAIM IS INCLUDED FOR corresponding equipment. USE - A method of focused laser beam processing, especially intended to remove or displace material at a surface of interaction. ADVANTAGE - The new method leads to partial absorption of the beam at the surface of interaction, to remove or displace material. The beam is formed in the interaction zone, in such a way that processing efficiency and stability, exceed those achievable by current techniques. Taking the example of cutting, the groove produced can be deeper for a given width. Excessive cutting width is avoided. All process parameters are optimized simultaneously by the control system, resulting in an increase of processing quality by avoidance of subjective errors. | |||||||
Details der Publikation | |||||||
| |||||||