Abstract: An optical system for a laser system for laser cutting includes a light guide for simultaneously coaxially transporting a first laser beam as a single-mode or quasi-single-mode laser beam and a second laser beam as a multi-mode laser beam, and an optical device arranged in a beam path of the first laser beam downstream of the light guide. The optical device is configured to impose a phase singularity and/or a polarization singularity on the first laser beam for generating an annular intensity distribution of the first laser beam with a central intensity minimum on an optical axis of the optical system.

Abstract: An apparatus for combining a plurality of coherent laser beams includes a splitting device configured to split an input laser beam into the plurality of coherent laser beams, a plurality of phase setting devices configured to adjust a respective phase of one of the plurality of coherent laser beams, and a beam combining device configured to combine the plurality of coherent laser beams, which emanate from a plurality of grid positions of a grid arrangement. The beam combining device includes a microlens arrangement having at least two microlens arrays. The apparatus further includes a controller configured to adjust a respective phase of a respective one of the plurality of coherent laser beams and/or vary a respective phase of a respective one of the plurality of coherent laser beams.

Abstract: A method for generating secondary radiation includes providing a target material in a target region, and applying a pulse sequence of laser pulses to the target material in the target region. Secondary radiation is generated as a result of interaction of the target material with the pulse sequence. The pulse sequence has a pulse train of at least two pre-pulses and a main pulse following the pulse train. A total energy of the pre-pulses of the pulse train is between 0.2 mJ and 10 mJ. A temporal pulse interval between successive pre-pulses of the pulse train is between 50 ps and 500 ns. A pulse energy of the main pulse is between 2 mJ and 50 mJ. A pulse duration of the main pulse is between 15 fs and 300 fs. A temporal pulse interval between the pulse train and the main pulse is between 1 ns and 1 ?s.

Abstract: A method for generating secondary radiation includes providing a target material in a target region, and applying a pulse sequence comprising laser pulses to the target material in the target region. Interaction of the target material with the pulse sequence generates secondary radiation. The pulse sequence includes a prepulse and a main pulse trailing the prepulse. A pulse energy of the prepulse is between 2 ?J und 200 ?J. A pulse duration of the prepulse is between 200 fs and 5 ps. A pulse energy of the main pulse is between 2 mJ and 50 mJ. A pulse duration of the main pulse is between 15 fs and 300 fs. A pulse time interval between the prepulse and the main pulse is between 1 ps and 1 ns.

Abstract: A method for separating an ultrathin glass using ultrashort laser pulses of an ultrashort pulse laser includes focusing the ultrashort laser pulses into the ultrathin glass such that a resulting focal zone is elongated in a beam direction and extends over an entire thickness of the ultrathin glass. The ultrashort laser pulses have a non-radially symmetric beam cross section perpendicular to a beam propagation direction. The method further includes introducing material modifications into the ultrathin glass along a separating line using the ultrashort laser pulses focused into the ultrathin glass, and separating the ultrathin glass along the separating line.

Abstract: A laser system for generating secondary radiation through interaction of a focused primary laser beam with a target material includes a laser beam source for providing a raw laser beam, and a beam guidance device for forming the focused primary laser beam from the raw laser beam. The focused primary laser beam is directed towards a target region in order to interact with the target material arranged in the target region. The beam guidance device includes a beam focusing device configured to form the primary laser beam by focusing a laser beam entering the beam focusing device, which corresponds to the raw laser beam. The beam focusing device includes at least two mirror elements spaced apart from one another. The beam focusing device has a numerical aperture between 0.001 and 0.01 provided that the primary laser beam propagates in a medium with a refractive index of less than 1.01.

Abstract: A method for laser welding of a workpiece includes providing a laser beam using a laser beam source, collimating the laser beam using a collimation optical unit, reshaping the collimated laser beam using a reshaping optical unit, and focusing the reshaped laser beam using a focusing unit. The focused laser beam is directed onto the workpiece to be welded. The reshaping optical unit has a first partial region in which at least one part of at least one axicon is embodied. At least a part of a beam cross-section of the collimated laser beam is directed onto the partial region of the reshaping optical unit.

Abstract: A method for laser processing of a workpiece that has a transparent material includes dividing an input laser beam into a plurality of sub-beams by using a beam splitting element, focusing the sub-beams coupled out of the beam splitting element to form multiple focus elements, and applying the focus elements to the material of the workpiece for the laser processing. The focus elements are moved relative to the material in a feed direction. A first sub-quantity of the focus elements is arranged in a first plane. A second sub-quantity of the focus elements is arranged in at least one other plane. The first plane and the at least one other plane are spaced apart in the feed direction. The first plane and the at least one other plane are orientated perpendicular to the feed direction.

Abstract: A method for separating a workpiece includes providing a machining laser beam that forms a plurality of focusing elements, introducing the focusing elements into a material of the workpiece, and moving the focusing elements parallel to an advancing line relative to the material. Material modifications are formed in the material along a machining surface that protrudes with respect to a partial region of the workpiece in a preferred direction. The method further includes subjecting the material to a heating laser beam that is moved relative to the material along a heating laser beam advancing line, thereby separating the material along the machining surface. The heating laser beam advancing line runs parallel to and is spaced apart from the advancing line with a positional offset that is anti-parallel to the preferred direction. The positional offset is at least 10% and at most 50% of a diameter of the heating laser beam.

Abstract: A diffractive optical element for imposing a phase distribution on a transverse beam profile of a laser beam includes surface elements that adjoin one another and form a sheet-like grating structure. Each surface element is assigned a phase shift value. The phase shift values define a two-dimensional phase distribution. The two-dimensional phase distribution has a beam center position, which defines a radial direction in the sheet-like grating structure. The surface elements are assigned to a plurality of angle segments. Each angle segment has an azimuthal segment width with respect to the beam center position. The phase shift values in the angle segments form radially symmetrical phase profiles respectively with respect to the beam center position. The radially symmetrical phase profiles form in the radial direction grating functions that have a same grating period. A segment grating phase is assigned to each of the grating functions.

Abstract: A laser system for laser machining a workpiece using an interference pattern includes at least one laser beam source for providing a plurality of coherent laser beams, an amplification device for forming amplified coherent laser beams by amplifying the plurality of coherent laser beams, a phase adjustment device for adjusting a phase difference between the plurality of coherent laser beams and/or the amplified coherent laser beams, and a beam convergence region in which output laser beams based on the amplified coherent laser beams or corresponding to the amplified coherent laser beams converge to form the interference pattern. At least beam portions of the different output laser beams converge in the beam convergence region.

Abstract: A transparent component includes a functionalized surface. The functionalized surface has dimples and laser-induced periodic surface structures. The functionalized surface is functionalized by the dimples and the laser-induced periodic surface structures. The dimples and the laser-induced periodic surface structures spatially overlap. The dimples have a depth between 100 nm and 2000 nm.

Abstract: A method for producing dimples on a surface of a transparent material using laser pulses of a short-pulse laser is provided. The method includes producing at least one dimple of the dimples on the surface of the transparent material by using a single laser pulse or a single laser burst.

Abstract: A method for laser processing a workpiece is provided. The workpiece includes a material transparent to a laser beam of the laser processing. The method includes splitting an input laser beam by using a beam splitter into a plurality of partial beams. The splitting of the input laser beam is performed by application of phases to a beam cross section of the input laser beam. The method further includes focusing the plurality of partial beams decoupled from the beam splitter by using a focusing optical unit. Multiple focus elements are formed by the focusing of the plurality of partial beams. The method further includes subjecting the material of the workpiece to at least a subset of the multiple focus elements. The application of the phases is performed in such a way that at least two of the multiple focus elements have different intensities.

Abstract: A processing optical unit for workpiece processing includes a birefringent polarizer configured to split at least one input laser beam into a pair of partial beams polarized perpendicularly to one another. The processing optical unit further includes a focusing optical unit arranged downstream of the birefringent polarizer in the beam path and configured to focus the pair of partial beams onto focus zones in a focal plane. The processing optical unit is configured to produce at least partly overlapping focus zones of the pair of partial beams.

Abstract: A method for severing a workpiece having a transparent material includes providing multiple focus elements using an input laser beam, applying the multiple focus elements to the material, thereby forming material modifications in the material along a predetermined processing line, and severing the material along the processing line by an etching process using a wet chemical solution. A temperature of the wet chemical solution during the etching process is at least 100° C. and/or at most 150° C.

Abstract: A welding optical unit for shaping a processing beam of a processing head of a welding apparatus includes a collimation lens, a focusing lens, and a beamforming insert for forming one or more spots of the processing beam on at least one workpiece to be processed. The beamforming insert has a base face and one or more side faces lying opposite the base face, which converge at a common point or in a common plateau of the beamforming insert.

Abstract: A device for processing a workpiece using a laser beam of a laser includes a retarder plate and a focusing device. The retarder plate is configured to apply a first location-dependent phase retardation to a first part of the laser beam having a first input polarization, and to apply a second location-dependent phase retardation to a second part of the laser beam having a second input polarization. The focusing device is configured to focus the laser beam in at least one focus zone. A beam form of the laser beam in the focus zone is determined by the first location-dependent phase retardation and the second location-dependent phase retardation. The at least one focus zone at least partially overlaps with the workpiece. The workpiece is subjected to laser radiation in the at least one focus zone and is thus processed.

Abstract: An apparatus for forming a laser beam can include a controllable spatial light modulator, a control device for controlling the light modulator, and a beam guiding optical unit, wherein the control device is configured to split a display plane of the light modulator into a plurality of display regions and to represent a first beam influencing structure in at least one first display region of the plurality of display regions and a second beam influencing structure in a second display region of the plurality of display regions, wherein the beam guiding optical unit is configured to cause the laser beam to interact along the direction of propagation thereof firstly with the first display region and then with the second display region.

Abstract: An apparatus for laser machining a workpiece includes a beam shaping device for forming a focal zone from an input laser beam incident on the beam shaping device, and a telescope device for imaging the focal zone into a material of the workpiece. The beam shaping device is configured to impose a phase on a beam cross section of the input laser beam in such a way that the focal zone extends along a longitudinal centre axis which is curved at least in certain portions. The telescope device is assigned a beam splitting device for splitting an output laser beam output coupled from the beam shaping device into a plurality of polarized partial beams, each of which has one of at least two different polarization states. The focal zone has an asymmetrical cross section in a plane oriented perpendicular to the longitudinal centre axis.