A method for laser cutting a workpiece having a thickness of less than 6 mm includes the steps of directing a first laser beam, a second laser beam, and a gas jet at an entrance surface of the workpiece such that the first and second laser beams at least partially overlap one another on the workpiece. The first laser beam has a smaller focus diameter than the second laser beam, a beam parameter product of the first laser beam is at most 5 mm*mrad, and a power proportion of the second laser beam of a total laser power is less than 20%. A cutting kerf with a broken cutting edge is formed on the entrance surface of the workpiece.

A laser processing apparatus of the present disclosure controls outputs of a blue laser oscillator and an infrared laser oscillator such that before a surface melting is detected on a workpiece, the workpiece is irradiated with at least blue laser light, and after the surface melting is detected on the workpiece, a power of infrared laser light with which the workpiece is irradiated is increased as compared to before the surface melting is detected.

The present application relates to an apparatus (10) for laser processing, comprising at least two laser sources, which are different from one another and are configured for supplying respective laser beams having wavelengths different from one another, a laser head (20), which can be operated as end tool of a laser machine tool (90) that can be configured for carrying out at least one type of laser processing operation that can be selected from a set of types of laser processing operations, and a set of orientable optical components (16) so as to provide a set of selectable optical paths for directing a laser beam supplied by a laser source of said at least two laser sources, and a control unit (30) coupled to the at least two laser sources, to the set of orientable optical components (16), and to the laser head (20) and configured for controlling the at least two laser sources, the set of orientable optical components (16), and the laser head (20) according to the type of laser processing operation selected from the set of types of laser processing operations, i.e., so as to supply and direct a laser beam associated to the respective type of processing operation onto a region of a work surface (110). The laser head (20) comprises a set of nozzles (40, 42, 44, 46) configured for directing at least one processing material onto the working region (110), which comprises at least one nozzle (40) configured for directing jets of powder of at least one material, preferably powder of metal material (in brief metal powder), as well as comprising at least one of the following: a) a first nozzle (42) configured for directing a metal wire onto the working region, preferably metal wire for laser welding; and b) a second nozzle (46) configured for directing an assist gas onto the working region, preferably an assist gas for laser welding, and wherein the control unit (30) is coupled to the set of nozzles and is configured for controlling at least one nozzle of said set of nozzles (40, 42, 44, 46) according to the type of associated and selected laser processing operation so as to control said at least one nozzle so that it will direct respective processing materials onto the working region (110) simultaneously with direction of the laser beam (L) associated to the type of laser processing operation selected.

A laser machining device includes: a broadband light source, which generates a broadband laser beam; a first lens unit to which the broadband laser beam is incident and having a first effective focal length; a second lens unit spaced apart from the first lens unit in a first direction and having a second effective focal length; a beam splitter disposed between the first lens unit and the second lens unit, and which is movable in the first direction and a direction opposite to the first direction within the first effective focal length from the first lens unit, and splits the broadband laser beam passing through the first lens unit into a plurality of sub-laser beams; and a focusing lens spaced apart from the second lens unit in the first direction, and which focuses the sub-laser beams passing through the second lens unit on a substrate.

A thermal processing apparatus and method in which a first laser source, for example, a CO.sub.2 emitting at 10.6 μm is focused onto a silicon wafer as a line beam and a second laser source, for example, a GaAs laser bar emitting at 808 nm is focused onto the wafer as a larger beam surrounding the line beam. The two beams are scanned in synchronism in the direction of the narrow dimension of the line beam to create a narrow heating pulse from the line beam when activated by the larger beam. The energy of GaAs radiation is greater than the silicon bandgap energy and creates free carriers. The energy of the CO.sub.2 radiation is less than the silicon bandgap energy so silicon is otherwise transparent to it, but the long wavelength radiation is absorbed by the free carriers.

The disclosure relates to processing machines and methods for producing three-dimensional components by irradiating powder with a processing beam, the machines including a container with a moveable support for the powder, as well as an irradiating device with a scanner device for aligning the processing beam on a processing field at an opening of the container. The irradiating device includes a heating device that includes a heating radiation source for generating a heating beam for heating the powder from above and including a beam shaping optical unit configured to convert a first beam profile of the heating beam into a second beam profile, e.g., a ring-shaped beam profile, of the heating beam.

A wavelength beam combining device includes: a polarization beam splitter configured to separate the plurality of laser beams into a plurality of first polarized light beams linearly polarized in a first polarization direction and a plurality of second polarized light beams linearly polarized in a second polarization direction that is orthogonal to the first polarization direction; a first polarization conversion element configured to convert the second polarized light beams into a plurality of third polarized light beams linearly polarized in the first polarization direction; a diffraction grating configured to diffract the plurality of first polarized light beams and generate a coaxially combined first wavelength-combined beam, and to diffract the plurality of third polarized light beams and generate a coaxially combined second wavelength-combined beam; and a polarization beam combiner configured to generate and emit a third wavelength-combined beam into which the first wavelength-combined beam and the second wavelength-combined beam have been coaxially combined.

A direct diode laser processing apparatus includes a laser oscillator that emits a multiple-wavelength laser beam, a transmission fiber that transmits the multiple-wavelength laser beam emitted from the laser oscillator, and a laser processing machine that condenses the multiple-wavelength laser beam transmitted through the transmission fiber and processes a workpiece. According to chromatic aberrations of the multiple-wavelength laser beam and the wavelength dependence of emissivity of the workpiece, a light intensity distribution of the multiple-wavelength laser beam in a thickness direction of the workpiece is provided with a plurality of peaks.

A laser array comprises first and second laser unit to respectively emit a first and second laser beams that propagate in a first and second directions and that are polarized in first and second polarization directions and a polarization coupling prism arranged to couple the two laser beams. The coupling prism comprises: a light entry surface to receive the first laser beam; a reflecting surface to reflect the first laser beam at an angle greater than the limit angle of total inner reflection; and a light exit surface through which the first laser beam exits the prism. The second laser unit is arranged relative to the polarization coupling prism to cause the second laser beam to impinge on and be reflected at the light exit surface in the same direction as the first laser beam exiting the prism, resulting in a collinear superposition of the first and second laser beams.

A power control method for a laser system comprising laser diodes arranged in diode banks is provided. Each diode bank comprises at least one of the laser diodes and has a maximum power. The method comprises operating a first diode bank of the diode banks to output a first power; and concurrently operating other of the diode banks to output other powers, at least one of the other powers being different than the first power.