A method for processing a workpiece using a pulsed laser beam includes beam shaping of the laser beam to form an elongated focus zone in the material of the workpiece. The beam shaping is carried out by using an arrangement of diffractive, reflective and/or refractive optical assemblies. The beam shaping includes focus-forming beam shaping to cause beam portions to enter at an entry angle to a beam axis of the laser beam for forming the elongated focus zone along the beam axis in the workpiece by way of interference, and phase-correcting beam shaping to counteract any influence of the interference by entrance of the laser beam into the workpiece. The method further includes setting beam parameters of the laser beam so that the material of the workpiece is modified in the elongated focus zone.

A method for monitoring a joining seam, in particular during joining by a laser beam, wherein in the processing direction before a processing point a joining site is measured in order to detect the position and geometry thereof, at least one position of a joining seam is determined from the position of the joining point, and in the processing direction after the processing point the joining seam is measured in order to detect the geometry thereof at the determined position. A device is also provided for carrying out said method and to a laser processing head equipped with such a device.

A method for monitoring a joining seam, in particular during joining by a laser beam, wherein in the processing direction before a processing point a joining site is measured in order to detect the position and geometry thereof, at least one position of a joining seam is determined from the position of the joining point, and in the processing direction after the processing point the joining seam is measured in order to detect the geometry thereof at the determined position. A device is also provided for carrying out said method and to a laser processing head equipped with such a device.

The present invention relates to a laser material processing system for processing a workpiece by means of a laser beam, comprising an optical system having at least one optical component for focusing the laser beam to form a focal point on the workpiece or in a defined position relative to the workpiece, at least one inertial sensor for detecting a transitional and/or rotational acceleration of the at least one optical component of the optical system and/or the workpiece, and a processing unit connected to the at least one inertial sensor for determining a relative transitional and/or rotational acceleration between the focal point and the workpiece.

The present invention relates to a laser material processing system for processing a workpiece by means of a laser beam, comprising an optical system having at least one optical component for focusing the laser beam to form a focal point on the workpiece or in a defined position relative to the workpiece, at least one inertial sensor for detecting a transitional and/or rotational acceleration of the at least one optical component of the optical system and/or the workpiece, and a processing unit connected to the at least one inertial sensor for determining a relative transitional and/or rotational acceleration between the focal point and the workpiece.

A method of generating uniform large-scale optical focus arrays (LOT As) with a phase spatial light modulator includes identifying and removing undesired phase rotation in the iterative Fourier transform algorithm (IFTA), thereby producing computer-generated holograms of highly uniform LOT As using a reduced number of iterations as compared to a weighted Gerch-berg-Saxton algorithm. The method also enables a faster compensation of optical system-induced LOT A intensity inhomogeneity than the conventional IFTA.

Disclosed embodiments include a head attached to a gantry. The head includes an optical assembly to focus a laser beam onto a surface of a material to be processed by a CNC machine and a measurement assembly with emitter(s) and detector(s), where the detector(s) are for measuring intensity of light emitted from the emitter(s) and reflected off the surface of the material. Processors are configured to (i) determine a material type of the material, (ii) determine a distance between the optical assembly and the material surface based on (a) measurement(s) of the intensity of the light emitted from the emitter(s) and reflected off the material surface, and (b) measurement parameter(s) associated with the determined material type, and (iii) control focusing of the laser beam onto the surface of the material based on the determined distance between the optical assembly and the surface of the material.

Disclosed embodiments include a head attached to a gantry. The head includes an optical assembly to focus a laser beam onto a surface of a material to be processed by a CNC machine and a measurement assembly with emitter(s) and detector(s), where the detector(s) are for measuring intensity of light emitted from the emitter(s) and reflected off the surface of the material. Processors are configured to (i) determine a material type of the material, (ii) determine a distance between the optical assembly and the material surface based on (a) measurement(s) of the intensity of the light emitted from the emitter(s) and reflected off the material surface, and (b) measurement parameter(s) associated with the determined material type, and (iii) control focusing of the laser beam onto the surface of the material based on the determined distance between the optical assembly and the surface of the material.

A method of processing a wafer having a plurality of intersecting streets on a face side thereof with protrusions on the streets includes a holding step of holding a protective sheet of a wafer unit on a holding table, an upper surface heightwise position detecting step of detecting a heightwise position of an upper surface of a reverse side of the wafer along the streets, and a laser beam applying step of applying a laser beam having a wavelength transmittable through the wafer to the wafer from the reverse side thereof along the streets while positioning a focused point of the laser beam within the wafer on the basis of the heightwise position, to thereby form modified layers in the wafer along the streets.

A method of processing a wafer having a plurality of intersecting streets on a face side thereof with protrusions on the streets includes a holding step of holding a protective sheet of a wafer unit on a holding table, an upper surface heightwise position detecting step of detecting a heightwise position of an upper surface of a reverse side of the wafer along the streets, and a laser beam applying step of applying a laser beam having a wavelength transmittable through the wafer to the wafer from the reverse side thereof along the streets while positioning a focused point of the laser beam within the wafer on the basis of the heightwise position, to thereby form modified layers in the wafer along the streets.