Abstract: A laser machining apparatus comprises a laser radiation source that generates laser radiation. A first and a second adaptive mirror are provided each having a pressure chamber connected to a pressure source and a mirror substrate that bounds the pressure chamber. An internal pressure in the pressure chamber can be changed with the aid of the pressure source in such a way that the mirror substrate deforms if the internal pressure in the pressure chamber changes. The mirror substrate of the first adaptive mirror has a thickness which varies at least within a region of the mirror substrate that bounds the pressure chamber. The mirror substrate of the second adaptive mirror has a thickness which is constant over the entire region over which the mirror substrate is deformable.

Abstract: A machining head of a laser machining apparatus comprises focusing optics which focus laser radiation. A measuring device measures changes of the focal length of the optics. The measuring device has a light source for generating measuring light different from the laser radiation. A light-exit window for the measuring light is imaged, with assistance of the focusing optics or a part thereof, onto a reflecting reference surface arranged to be stationary relative to the exit window and the focusing optics. A light sensor detects measuring light that has emerged from the exit window, has passed through the focusing optics or the part thereof, was reflected on the reflecting surface, and has again passed through the focusing optics or the part thereof. An evaluating device ascertains the change in the focal length of the focusing optics from measuring signals made provided by the light sensor.

Abstract: A method and device for the detection and monitoring of the contamination of an optical component in a device for laser material processing, which emits a process laser beam through or onto the optical component. A measurement beam emitted by a light source is projected under an angle of incidence onto an optical surface of the optical component. The beam reflected from the outer surface of the protective window under the angle of reflection corresponding to the angle of incidence is conducted through an aperture stop onto a first light-sensitive detector so as to record the intensity of the reflected beam. The intensity of the scattered radiation, scattered diffusely from the optical surface of the component under a scattering angle, is recorded by a second light-sensitive detector. The degree of the contamination of the component is determined from the recorded intensities of the reflected beam and the scattered radiation.

Abstract: A machining head of a laser machining apparatus comprises focusing optics which focus laser radiation in a focal spot. A measuring device measures changes of the focal length of the focusing optics. The measuring device has a light source for generating measuring light that is different from the laser radiation. A light-exit window for the measuring light is imaged, with the assistance of the focusing optics or a part thereof, onto a reflecting reference surface which is arranged to be stationary relative to the light-exit window and the focusing optics. A light sensor detects measuring light that has emerged from the light-exit window, has passed through the focusing optics or the part thereof, was reflected on the reflecting surface, and has again passed through the focusing optics or the part thereof. An evaluating device ascertains the change in the focal length of the focusing optics from measuring signals made provided by the light sensor.

Abstract: A laser machining apparatus comprises a laser radiation source that generates laser radiation. A first and a second adaptive mirror are provided each having a pressure chamber connected to a pressure source and a mirror substrate that bounds the pressure chamber. An internal pressure in the pressure chamber can be changed with the aid of the pressure source in such a way that the mirror substrate deforms if the internal pressure in the pressure chamber changes. The mirror substrate of the first adaptive mirror has a thickness which varies at least within a region of the mirror substrate that bounds the pressure chamber. The mirror substrate of the second adaptive mirror has a thickness which is constant over the entire region over which the mirror substrate is deformable.

Abstract: The invention relates to a method for detecting and adjusting the focus (F) of a laser beam when laser machining workpieces, having the following steps: a.) guiding and focusing a laser beam of a machining laser (1) emitted from a machining head (48) into a machining point (26) on or with respect to the surface (49) of a workpiece to be machined, wherein the focusing takes place by means of an optical focusing element (2); b.) guiding and focusing the radiation (28, 31) emitted by at least one first adjusting light source (22) and one second adjusting light source (23) onto the surface (49) of the workpiece to be machined, wherein the wavelengths of the radiation emitted by the adjusting light sources (22, 23) are different; c.

Abstract: A method and device for the detection and monitoring of the contamination of an optical component in a device for laser material processing, which emits a process laser beam through or onto the optical component. A measurement beam emitted by a light source is projected under an angle of incidence onto an optical surface of the optical component. The beam reflected from the outer surface of the protective window under the angle of reflection corresponding to the angle of incidence is conducted through an aperture stop onto a first light-sensitive detector so as to record the intensity of the reflected beam. The intensity of the scattered radiation, scattered diffusely from the optical surface of the component under a scattering angle, is recorded by a second light-sensitive detector. The degree of the contamination of the component is determined from the recorded intensities of the reflected beam and the scattered radiation.

Abstract: The invention relates to a method for detecting and adjusting the focus (F) of a laser beam when laser machining workpieces, having the following steps: a.) guiding and focusing a laser beam of a machining laser (1) emitted from a machining head (48) into a machining point (26) on or with respect to the surface (49) of a workpiece to be machined, wherein the focusing takes place by means of an optical focusing element (2); b.) guiding and focusing the radiation (28, 31) emitted by at least one first adjusting light source (22) and one second adjusting light source (23) onto the surface (49) of the workpiece to be machined, wherein the wavelengths of the radiation emitted by the adjusting light sources (22, 23) are different; c.

Abstract: A process and an arrangement are described by means of which a plurality of ray bundles emitted from individual radiation sources are combined with the aid of an imaging optics system. The individual radiation sources are in this connection arranged on at least one curve surrounding the optical axis of the imaging optics system. The individual ray bundles are substantially linearly polarised. The bundles are reflected on their path to the superimposition point at least at a surface whose reflection capability is polarisation-dependent. The polarisation direction of the ray bundles coming from the individual radiation sources is in this connection aligned so that the first reflection at the surface takes place with low loss, whereas a possible second reflection after previous reflection at the workpiece takes place with high loss. In this way the individual radiation sources are protected against damaging back-reflections.

Abstract: A type of "light barrier" is used to monitor the functionality of the transparent protective element (5) of a transparent laser optical system: additional light (15) is coupled into a lateral surface of the protective element (5) at an angle which deviates from the incidence direction of the laser beam (1, 2). Said light traverses the material of the protective element (5) and then exits again via the lateral surface, where it is detected by a light detector (16). Cracks and fractures of the protective element (5) can be detected by a change in the light received in the light detector (16). If appropriate, this measurement is supplemented by the measurement of the temperature difference between inflowing and outflowing cooling water, as well as by radiation temperature sensors (14) which monitor the local temperature distribution in the protective element (5).

Abstract: A device for machining a workpiece, for example by welding or cutting, a machining laser beam which passes through a channel in a laser machining head. An observation channel is provided in the laser machining head through which rays from the workpiece pass. A component of the rays from a specific geometrical region of the workpiece is deflected through the observation channel to a detector mounted on the laser machining head.