Method and device for machining by means of interfering laser radiation
AssigneesFraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V., Friedrich-Schiller-Universität Jena
InventorsMalte Per Siems, Stefan Nolte, Daniel Richter, Ria Krämer, Thorsten Albert Goebel
Life of this patent
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Abstract
A method and an apparatus for processing an object by generation of laser radiation as a collimated laser beam, influencing the intensity distribution and/or the phase progression over the cross section of the laser beam, splitting the laser beam into two partial beams, and deflection and focusing of the partial beams so that the partial beams are superimposed in a processing zone in the material of the object.
Claims14
A method for processing an object (1) by means of interfering laser beams, comprising the following process steps:
- generating laser radiation as a collimated laser beam (3);
- influencing at least one of an intensity distribution and phase progression over a cross section of the collimated laser beam (3) using a phase mask comprising a plate of transparent material, the phase mask being configured to cause laser radiation incident perpendicular to a plane of the plate to travel different optical path lengths through the plate over the cross-section of the laser beam, and to compensate thereby for deviations and non-ideal properties of other optical components used;
- splitting the collimated laser beam (3) into two partial beams (6, 7), and
- deflecting and focusing of each of the two partial beams (6, 7) so that the two partial beams (6, 7) are superimposed in a processing zone (10) in the object (1);
- wherein the deflecting and focusing of each of the partial beams (6, 7) comprises interacting with each one of the partial beams (6, 7) individually to apply an aberration correction separately to each of the partial beams (6, 7) using an imaging lens, and controlling a period progression of a modification to be generated in the object (1) by the two partial beams (6, 7) superimposed in the processing zone (10) using at least one adaptive optical element.
An apparatus for processing an object by means of interfering laser beams, comprising:
- a laser (2) configured to generate laser radiation as a collimated laser beam (3),
- a phase mask (4, 4a, 4c) comprising a plate of transparent material, configured to modify a least one of an intensity distribution and a phase progression of the laser radiation over a cross-section of the collimated laser beam (3), the phase mask being further configured to cause laser radiation incident perpendicular to a plane of the plate to travel different optical path lengths through the plate over the cross-section of the laser beam, and to compensate thereby for deviations and non-ideal properties of other optical components used,
- a beam splitter (5) configured to split the collimated laser beam (3) into two partial beams (6, 7), and
- a deflection and focusing optics (8, 9) configured to superimpose the partial beams in a processing zone (10) in the object (1);
- wherein the deflection and focusing optics (8, 9) comprising at least one adaptive optical element and an imaging lens, the deflection and focusing optics (8, 9) being configured to interact with each of the partial beams to apply an aberration correction separately to each of the partial beams (6, 7) using the imaging lens, and to control a period progression of a modification to be generated in the object (1) by the two partial beams (6, 7) superimposed in the processing zone (10) using the at least one adaptive optical element.
Dependencies are inferred from the claim text.