A device (1) for applying light (4) to an inner surface (2) of a cylinder (3), comprising a homogenizer (14), into which light (4) can enter and from which the light (4) can exit, wherein the homogenizer (14) has a cylindrical internal surface (15), on which the light (4) can be reflected after entering and before exiting, and also comprising ways for introducing light (4) into the homogenizing means (14), and focusing arrangements, which can focus light (4) exiting from the homogenizer (14) onto the inner surface (2) of the cylinder (3) to which light (4) is to be applied.

An optical delivery waveguide for a material laser processing system includes a small lens at an output end of the delivery waveguide, transforming laser beam divergence inside the waveguide into a spot size after the lens. By varying the input convergence angle and/or launch angle of the laser beam launched into the waveguide, the output spot size can be continuously varied, thus enabling a continuous and real-time laser spot size adjustment on the workpiece, without having to replace the delivery waveguide or a process head. A divergence of the laser beam can also be adjusted dynamically and in concert with the spot size.

A laser processing apparatus includes a light source configured to generate a laser beam, and a light converging optical system configured to converge laser beam to a focal point at an object to be processed, the light converging optical system including a through-hole optical element and a composite optical element under the through-hole optical element, wherein the through-hole optical element includes a first recess portion configured as a concave mirror at a lower surface of the through-hole optical element, and wherein an upper surface of the composite optical element is convex and includes a first region configured to reflect the laser beam and a second region configured to transmit the laser beam.

Machining device comprising an optical trepanation head (1), comprising an opto-mechanical system having a head body (21) provided with a rotating device (22), a picosecond or femtosecond pulsed laser source (3), and at least one optical fiber (4) wherein the rotation device (22) of the opto-mechanical system (2) comprises a rotative diffraction grating (R1). Machining process by means of optical trepanation using such a device.

A method and device for laser cladding by independently heating the cladding material and the surface of the workpiece consist in formation of the series of parallel annular laser beams, possibly different wavelengths, with an adjustable distribution of laser radiation power across the annular beams. The annular beams are transformed into a series of conical beams which are separately focused along a single optical axis, along which the cladding material is fed. The device can be supplemented with a cylindrical mirror for the multipass laser radiation through the stream of cladding material with the possibility of the laser radiation return to the laser resonator.

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.

A method for joining busbars includes reshaping a raw laser beam to obtain a reshaped laser beam. The reshaped laser beam comprises a core focus portion and at least one ring focus portion. The core focus portion and the ring focus portion are coaxial with respect to one another. The ring focus portion surrounds the core focus portion. The method further includes directing the reshaped laser beam to a plurality of busbars to weld the plurality of busbars to one another along at least one weld seam.

A method for laser welding of a workpiece includes welding at a corner joint of two workpiece parts of the workpiece by a welding laser beam to create an aluminum connection between the two workpiece parts, and feeding an output laser beam into a first end of a multiclad fiber to generate the welding laser beam. The multiclad fiber comprises at least a core fiber and a ring fiber surrounding the core fiber. A first portion LK of a laser power output of the output laser beam is fed into the core fiber, and a second portion LR of the laser power output of the output laser beam is fed into the ring fiber. A second end of the multiclad fiber is reproduced on the workpiece. The method further includes welding the workpiece by deep welding.

A processing machine includes a laser irradiation device that emits an annular laser beam, and a wire feeding device that feeds a wire from an inside of the annular laser beam. When a workpiece irradiation proportion parameter (WIP) represented by an equation WIP=P.sub.wp/P (P.sub.wp: laser beam power introduced onto a workpiece surface when the wire exists in an irradiation region of the laser beam, P: the laser beam power introduced onto the workpiece surface when the wire does not exist in the irradiation region) is defined, a control device controls the wire feeding device so that a wire end abuts on the workpiece surface at a beginning of additive manufacturing. The control device determines initial power P.sub.0 based on the WIP at the beginning of the additive manufacturing, and controls the laser irradiation device so that the workpiece is irradiated with the laser beam at the initial power P.sub.0.

A method for selective laser-induced etching of a microhole into a workpiece includes creating a modification in the workpiece that extends from an entrance side to an exit side of the workpiece. The modification is created by a laser pulse that has an annular transverse intensity distribution. The modification delimites a cylindrical body from a residual material surrounding the modification. The method further includes introducing the workpiece with the modification into a wet-chemical etching bath for structurally separating the cylindrical body from the residual material.