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.

A laser irradiation method sets scan lines in an x direction in parallel, and in a y direction to be separate by an inter-scan-line distance Py corresponding to laser irradiation areas of a processing target object, orients a length direction of a linear laser spot with length Wy and width Wx in the y direction, and irradiates target object with the laser spot in each of irradiation positions arranged at width direction intervals while moving the laser spot relative to the target object along the scan lines. The method includes determining the inter-scan-line distance Py, the width direction interval , and a position shift quantity x (where, 0<x<) so that the irradiation positions on adjacent scan lines are shifted in the x direction by the position shift quantity x and a cumulative value of the applied laser intensity is substantially equalized.

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 thermal processing apparatus and method in which a first laser source, for example, a CO.sub.2 emitting at 10.6 ?m 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.

A method for joining copper hairpins includes providing at least two ends to be joined to one another of the copper hairpins, and joining the copper hairpins. The copper hairpins are joined by laser beam welding with a machining beam having a wavelength of less than 1000 nm.

If an optical path length of an optical system is reduced and a length of a laser light on an irradiation surface is increased, there occurs curvature of field which is a phenomenon that a convergent position deviates depending on an incident angle or incident position of a laser light with respect to a lens. To avoid this phenomenon, an optical element having a negative power such as a concave lens or a concave cylindrical lens is inserted to regulate the optical path length of the laser light and a convergent position is made coincident with a irradiation surface to form an image on the irradiation surface.

The present invention generally relates to an optical system that is able to reliably deliver a uniform amount of energy across an anneal region contained on a surface of a substrate. The optical system is adapted to deliver, or project, a uniform amount of energy having a desired two-dimensional shape on a desired region on the surface of the substrate. Typically, the anneal regions may be square or rectangular in shape. Generally, the optical system and methods of the present invention are used to preferentially anneal one or more regions found within the anneal regions by delivering enough energy to cause the one or more regions to re-melt and solidify.

A laser processing apparatus for processing a workpiece by applying laser beam to the workpiece, including: a laser oscillator capable of emitting laser beam; a beam rotator that converts the laser beam emitted from the laser oscillator into a circular beam having a predetermined diameter; a beam shaper on which the circular beam emitted from the beam rotator is incident and from which a polygonal beam is emitted; and a focusing optical system that focuses the polygonal beam emitted from the beam shaper on the workpiece, wherein the beam shaper is a DOE-type beam shaper, and the outer peripheral diameter of the circular beam incident on the DOE-type beam shaper is larger than a standard incident beam diameter preset for the DOE-type beam shaper.

A system includes a laser source, a galvanometer mirror system, an f-theta scan lens and an acousto-optic deflector (AOD) system. The AOD system is operated to deflect a beam path along which a laser beam propagates in a manner that corrects for scan field distortion induced by one or both of the f-theta lens and galvanometer mirror system.

There is provided an additive manufacturing device including a control device of controlling a relative posture of a heat retaining light beam irradiation device to a melting light beam irradiation device, in a state where a heat retaining light irradiation range of a heat retaining light beam larger than a melting light irradiation range of a melting light beam is overlapped with the melting light irradiation range, and such that a size of the heat retaining light irradiation range is changeable with respect to a size of the melting light irradiation range.