The laser apparatus includes a laser generator configured to generate at least one input beam traveling from one side to the other side in one direction and an optical system including an F-theta lens, which includes a plurality of spherical lenses. The F-theta lens includes a first lens including a first one surface that is convex toward the one side and a first other surface that is convex toward the other side, a second lens including a second one surface that is convex toward the one side and a second other surface that is concave toward the other side, a third lens including a third one surface that is concave toward the one side and a third other surface that is convex toward the other side, and a fourth lens including a fourth one surface that is convex toward the one side and a fourth other surface that is a plane perpendicular to the other side

A field mapping optical system and method for converting a light beam having a known spatially coherent first optical field to a second optical field with a required intensity distribution and flat wavefront at a desired distance from the system, by creating an intermediate optical field, between the first and second optical fields, the intermediate optical field being derived from the inverse Fourier transform of the second optical field. The optical system provides a compact and simplified field mapper.

Multi-beam, multi-wavelength processing systems include two or more lasers configured to provide respective beams to a substrate. The beams have wavelengths, pulse durations, beam areas, beam intensities, pulse energies, polarizations, repetition rates, and other beam properties that are independently selectable. Substrate distortion in processes requiring local heating can be reduced by preheating with a large area beam at a first wavelength followed by exposure to a focused beam at a second wavelength so as to heat a local area to a desired process temperature. For some processing, multiple wavelengths are selected to obtain a desired energy deposition within a substrate.

A method of laser welding a workpiece stack-up (10) that includes at least two overlapping metal workpieces (12, 14) comprises advancing a laser beam (24) relative to a plane of a top surface (20) of the workpiece stack-up (10) from a start point (84) to an end point (86) along a beam travel pattern (78) at a high laser beam travel speed of greater than 8 meters per minute. The two or more overlapping metal workpieces (12, 14) may be steel workpieces or they may be aluminum workpieces, and at least one of the metal workpieces (12, 14) includes a surface coating (40). Advancing the laser beam (24) along the beam travel pattern (78) forms a weld joint (76), which includes resolidified composite workpiece material derived from each of the metal workpieces (12, 14) penetrated by a molten weld pool (80), that fusion welds the metal workpieces (12, 14) together. The relatively high laser beam travel speed contributes to improve strength properties of the weld joint (76).

A laser processing apparatus capable of imparting heat sealing properties to a biaxially stretched polyester film through a method having high efficiency and high safety. The laser processing apparatus includes a laser oscillator, where a film formed of a single layer of a biaxially stretched polyester or a laminate containing a layer of a biaxially stretched polyester on the surface is irradiated with laser light emitted from the laser oscillator, to impart heat sealing properties to a region of the film irradiated with the laser light. The laser processing apparatus may include an optical element which shapes a spot profile of the laser light into a predetermined profile, and may also include a film mounting part which mounts the film.

The device comprises a welding unit with a tube (3), a laser radiation unit (1) radiating in direction of the tube axis (3.0), and a mandrel (4) which is connected to the tube (3) via a holding unit which is formed, e.g., by two spacer elements (5.1) and which is coaxially arranged relative to and in the tube (3). The tube (3) and the circumferential surface of the mandrel (4) are reflective of the laser radiation of the laser radiation unit (1) such that through multiple reflections between the tube (3) and the mandrel (4) the laser radiation is deflected toward the beam output-side tube end (3.2) and is shaped annularly.

A beam shaper is provided that includes two optical elements arranged one behind the other along an optical axis. Each optical element has at least one optically active freeform surface. The optical elements are arranged displaceable by a relative displacement against each other along at least one axis substantially perpendicular to the optical axis. The optically active freeform surfaces have a height profile, which is a polynomial expansion having polynomial coefficients different from zero in finitely many polynomial orders. At least one polynomial coefficient, assigned to a polynomial order greater than three, is different from zero. The height profiles of the at least two freeform surfaces are selected such that input beams distributed rotationally symmetric about the optical axis with a Gaussian beam density profile are diffracted into output beams which are limited in a receiving plane within a rectangular cross section and are uniformly distributed about the optical axis.

A laser processing apparatus includes: a chuck table that holds a workpiece; a laser beam applying unit that applies a pulsed laser beam having a predetermined line width to the workpiece held by the chuck table; and a processing feeding unit that performs relative processing feeding of the chuck table and the laser beam applying unit. The laser beam applying unit includes: a laser oscillator that oscillates the pulsed laser beam; a focusing device that focuses the pulsed laser beam oscillated by the laser oscillator; and a pulse width adjustment unit that is disposed between the laser oscillator and the focusing device and that generates a time difference in a wavelength region of the pulsed laser beam in the predetermined line width, thereby adjusting the pulse width.

Various embodiments of the present invention relate to a method for welding a workpiece comprising the steps of: making a first weld at a first position on said workpiece with a high energy beam, deflecting the high energy beam with at least one deflection lens for making a second weld at a second position on said workpiece, focusing the high energy beam on said workpiece with at least one focusing lens, shaping the high energy beam on said workpiece with at least one astigmatism lens so that the shape of the high energy beam on said workpiece is longer in a direction parallel to a deflection direction of said high energy beam than in a direction perpendicular to said deflection direction of said high energy beam. The invention is also related to the use of an astigmatism lens and to a method for forming a three dimensional article.

A laser radiation optical system for laser doping and post-annealing, the laser radiation system including A. a laser apparatus configured to generate pulsed laser light that belongs to an ultraviolet region, B. a stage configured to move a radiation receiving object in an at least one scan direction, the radiation receiving object being an impurity source film containing at least an impurity element as a dopant and formed on a semiconductor substrate, and C. an optical system including a beam homogenizer configured to shape the beam shape of the pulsed laser light into a rectangular shape and generate a beam for laser doping and a beam for post-annealing that differ from each other in terms of a first beam width in the scan direction but have the same second beam width perpendicular to the scan direction.