Abstract: A processing head for a laser processing device adapted for processing a workpiece using laser radiation has: adjustable focusing optics to focus laser radiation in a focal spot having an adjustable distance from the processing head; an optical coherence tomograph to measure a distance between the processing head and the workpiece by measuring an optical interference between measuring light reflected by the workpiece and measuring light not reflected by the workpiece; a path length modulator that can change, synchronously with and dependent on a change of the focal spot distance from the processing head, an optical path length in an optical path along which measuring light propagates; a scanning device, which deflects the laser radiation in different directions; and a control device, which i) controls a focal length of the focusing optics in such a way that the focal spot is situated at a desired location on the workpiece, ii) receives, from the coherence tomograph, information representing the distance betwe

Abstract: The present disclosure concerns a device for distance measurement for a laser processing system. The device comprises a light source, which is configured to generate a primary beam for direction onto a workpiece, at least one detection device configured to record a secondary beam reflected from the workpiece, at least one optical amplifier configured to amplify the primary beam and/or the secondary beam, and an evaluation unit configured to evaluate interference between spectral components in the frequency domain.

Abstract: A method for measuring the depth of the vapour cavity during an industrial machining process employs a high-energy beam. An optical measuring beam is directed towards the base of a vapour cavity. An optical coherence tomograph generates interference factors or other raw measurement data from reflections of the measurement beam. An evaluation device generates undisturbed measurement data, wherein raw measurement data that is generated at different times is processed together in the course of a mathematical operation. This operation can be a subtraction or a division. Slowly changing interference factors can thus be eliminated. An end value for the distance to the base of the vapour cavity is calculated from the undisturbed measurement data using a filter. As a result, the depth of the vapour cavity can be determined, in the knowledge of the distance at a part of the surface of the work piece that is not exposed to the high-energy beam.

Abstract: A chromatic confocal measuring device for the measurement of distances and/or thicknesses of several locations has a light source that emits polychromatic measuring light through a light exit surface. The light source is a laser pumped luminophore-based light source and has an oblong exit surface. The measuring device further has at least one first confocal aperture through which the measuring light passes and which comprises a plurality of punctiform orifices or at least one slit-shaped orifice. The measuring device also includes imaging optics configured to cause a chromatic focus shift of the measuring light and to image the first confocal aperture in a measurement volume so that different wavelengths are focused at different heights.

Abstract: A processing head for a laser processing device adapted for processing a workpiece using laser radiation has: adjustable focusing optics to focus laser radiation in a focal spot having an adjustable distance from the processing head; an optical coherence tomograph to measure a distance between the processing head and the workpiece by measuring an optical interference between measuring light reflected by the workpiece and measuring light not reflected by the workpiece; a path length modulator that can change, synchronously with and dependent on a change of the focal spot distance from the processing head, an optical path length in an optical path along which measuring light propagates; a scanning device, which deflects the laser radiation in different directions; and a control device, which i) controls a focal length of the focusing optics in such a way that the focal spot is situated at a desired location on the workpiece, ii) receives, from the coherence tomograph, information representing the distance betwe

Abstract: A device for machining material by means of laser radiation, including a focusing optics for focusing a laser beam onto a workpiece and an adjusting optics for adjusting the intensity distribution comprising at least two plate-shaped optical elements which are arranged one behind the other in the beam path of the laser beam, which are rotatable relative to one another in the circumferential direction, and which each have a surface with a circular pattern of sector-shaped facets which, in the circumferential direction, are alternately inclined with respect to the respective plate plane.

Abstract: The present disclosure concerns a device for distance measurement for a laser processing system. The device comprises a light source, which is configured to generate a primary beam for direction onto a workpiece, at least one detection device configured to record a secondary beam reflected from the workpiece, at least one optical amplifier configured to amplify the primary beam and/or the secondary beam, and an evaluation unit configured to evaluate interference between spectral components in the frequency domain.

Abstract: A chromatic confocal distance sensor has a housing in which a polychromatic light source, imaging optics having a longitudinal chromatic aberration, a spectrometer and a planar beam splitter surface are arranged. These lie in the light path of the measurement light between the light source and the imaging optics and between the imaging optics and the spectrometer. A first diaphragm is arranged in the light path between the light source and the beam splitter surface, and a second diaphragm is arranged in the light path between the beam splitter surface and the spectrometer. The diaphragms are arranged mirror-symmetrically with respect to the beam splitter surface. The measurement light propagates as a free beam inside the housing. The beam splitter surface, the first diaphragm and the second diaphragm are fastened together on a carrier which has an isotropic thermal expansion coefficient. This way, temperature changes cannot significantly affect the measurement accuracy.

Abstract: A method for measuring the depth of the vapour cavity during an industrial machining process employs a high-energy beam. An optical measuring beam is directed towards the base of a vapour cavity. An optical coherence tomograph generates interference factors or other raw measurement data from reflections of the measurement beam. An evaluation device generates interference-suppressed measurement data, wherein raw measurement data that is generated at different times is processed together in the course of a mathematical operation. This operation can be a subtraction or a division. Slowly changing interference factors can thus be eliminated. An end value for the distance to the base of the vapour cavity is calculated from the interference-suppressed measurement data using a filter. As a result, the depth of the vapour cavity can be determined, in the knowledge of the distance at a part of the surface of the work piece that is not exposed to the high-energy beam.

Abstract: A device for measuring a distance to an object comprises a beam splitter for splitting broadband coherent light emitted by a light source in measuring light which is guided through an object arm to the object to be measured and in reference light which is guided to a reference arm. The object arm includes a focusing optics with a focus movable along an optical axis of the object arm. The focusing optics comprises a movable optical element and is configured such that a movement of the movable optical element along the optical axis causes a higher movement of the focus of the focusing optics along the optical axis. The movable optical element of the focusing optics is coupled to the reference arm such that the optical path length of the reference arm can be tracked synchronously with and dependent on the movement of the focus of the focusing optics.

Abstract: A chromatic confocal measuring device includes a light source, which emits light of a plurality of wavelengths, and a first beam splitter, via which the light from the light source into an imaging optical unit having chromatic aberration on. Light reflected from the measurement object is imaged by the imaging optical unit and the first beam splitter onto a first confocal detection stop arrangement, such that the first confocal detection stop arrangement functions as a confocal aperture. Light incident through the first detection stop arrangement is detected and evaluated by a first detection device. The measuring device has a first slit stop, which functions as a confocal aperture of the measuring device. The measuring device additionally includes a second detection device and a second beam splitter, wherein the second beam splitter splits the light reflected from the measurement object into a first and a second partial beam, which image the same spatial region of the measurement object.

Abstract: A distance measuring device for measuring a distance to an object to be measured comprises a beam splitter for splitting broadband coherent light emitted by a light source in measuring light which is guided through an object arm to the object to be measured and in reference light which is guided to a reference arm. A focusing optics with a focus being movable along an optical axis of the object arm is provided in the object arm, wherein the focusing optics comprises a movable optical element and is configured such that a movement of the movable optical element along the optical axis causes a higher movement of the focus of the focusing optics along the optical axis and wherein the movable optical element of the focusing optics is coupled to the reference arm such that the optical path length of the reference arm can be tracked synchronously with and dependent on the movement of the focus of the focusing optics.

Abstract: The invention relates to an optical measuring process for acquiring a surface topography of a measurement object. To this end, a measuring device with a measuring head in a measuring head guide device is provided for chromatic confocal acquisition of the surface topography or for spectral interferometric OCT acquisition of the distance to the surface topography. Firstly, spectrally broadband light of a light source from a fibre array with i fibres of i measurement spots is directed onto the measurement object via a common measuring head optic, with formation of a spot array of i measurement spots. i reflection spectra of the i measurement channels are then acquired and digitized. Finally, the digitized reflection spectra are evaluated with removal of time variations of systematic measurement errors and time-related deviation movements of the measuring head guide device.

Abstract: A chromatic confocal distance sensor has a housing in which a polychromatic light source, imaging optics having a longitudinal chromatic aberration, a spectrometer and a planar beam splitter surface are arranged. These lie in the light path of the measurement light between the light source and the imaging optics and between the imaging optics and the spectrometer. A first diaphragm is arranged in the light path between the light source and the beam splitter surface, and a second diaphragm is arranged in the light path between the beam splitter surface and the spectrometer. The diaphragms are arranged mirror-symmetrically with respect to the beam splitter surface. The measurement light propagates as a free beam inside the housing. The beam splitter surface, the first diaphragm and the second diaphragm are fastened together on a carrier which has an isotropic thermal expansion coefficient. This way, temperature changes cannot significantly affect the measurement accuracy.

Abstract: A device for machining material by means of laser radiation, including a focusing optics for focusing a laser beam onto a workpiece and an adjusting optics for adjusting the intensity distribution comprising at least two plate-shaped optical elements which are arranged one behind the other in the beam path of the laser beam, which are rotatable relative to one another in the circumferential direction, and which each have a surface with a circular pattern of sector-shaped facets which, in the circumferential direction, are alternately inclined with respect to the respective plate plane.

Abstract: According to a method for measuring the distance between a workpiece and a machining head of a laser machining apparatus, a machining head is provided, which has a housing that has an interior and an opening for emergence of the laser radiation from the machining head. The laser radiation is directed on to the workpiece, after it has passed through the interior and the opening. An object beam is directed on to the workpiece by a light source of an optical coherence tomograph in such a manner that the object beam passes through the interior and the opening before being incident upon the workpiece. In addition to the object beam, a measuring beam passes through the interior. The measuring beam is used to compensate falsifications of the measured distance that have been caused by pressure fluctuations in the interior. The measuring beam in this case may be reflected at a reflective face that is formed on an inner face of an outlet nozzle that comprises the opening, which inner face delimits the interior.

Abstract: The invention relates to an optical measuring process for acquiring a surface topography of a measurement object. To this end, a measuring device with a measuring head in a measuring head guide device is provided for chromatic confocal acquisition of the surface topography or for spectral interferometric OCT acquisition of the distance to the surface topography. Firstly, spectrally broadband light of a light source from a fibre array with i fibres of i measurement spots is directed onto the measurement object via a common measuring head optic, with formation of a spot array of i measurement spots. i reflection spectra of the i measurement channels are then acquired and digitized. Finally, the digitized reflection spectra are evaluated with removal of time variations of systematic measurement errors and time-related deviation movements of the measuring head guide device.

Abstract: The invention relates to an optical measuring process for acquiring a surface topography of a measurement object. To this end, a measuring device with a measuring head in a measuring head guide device is provided for chromatic confocal acquisition of the surface topography or for spectral interferometric OCT acquisition of the distance to the surface topography. Firstly, spectrally broadband light of a light source from a fiber array with i fibers of i measurement spots is directed onto the measurement object via a common measuring head optic, with formation of a spot array of i measurement spots. i reflection spectra of the i measurement channels are then acquired and digitized. Finally, the digitized reflection spectra are evaluated with removal of time variations of systematic measurement errors and time-related deviation movements of the measuring head guide device.

Abstract: The invention relates to a test device for testing a bonding layer between wafer-shaped samples and a test process for testing the bonding layer. The test device comprises a measuring head for an OCT process that is configured to direct an optical measuring beam at a composite comprising at least two wafer-shaped samples with a bonding layer positioned between them. An optical beam splitter is configured to divert an optical reference beam as a reference arm for distance measurements. An evaluation unit is configured to evaluate layer thickness measurements without a reference arm and distance measurements with a reference arm. An optical switch device is configured to connect and disconnect the reference arm.

Abstract: A method for measuring the penetration depth of a laser beam into a work-piece. A focusing optical unit arranged in a machining head focuses the laser beam in a focal spot. The focal spot produces a vapor capillary in the workpiece. An optical coherence tomograph produces a first and a second measurement beam. The first measurement beam is directed at a first measurement point at the base of the vapor capillary in order to thereby measure a first distance between a reference point and the first measurement point. At the same time, the second measurement beam is directed at a second measurement point on a surface of the workpiece which faces the machining head and which is outside of the vapor capillary measuring a second distance between the reference point and the second measurement point. The depth of penetration of the laser beam is the difference between the second and the first distances.