Abstract: A method of laser welding of two members by their respective edges, on a first surface of a slideway section, wherein at least a first one of said members is welded by application of two parallel laser beams from a second surface of the slideway section, with a distance between the beams approximately corresponding to the thickness of the first member, to obtain a laser transmission welding in a single run.

Abstract: Aims are to provide a tubular-body residual-stress improving apparatus and an adjustment method thereof capable of adjusting irradiation position with favorable reproducibility, even when an optical fiber is eccentric. In the tubular-body residual-stress improving apparatus, an optical control unit (5) includes a rotational hold mechanism (9) for holding an optical fiber (6) in a manner that the optical fiber (6) is rotatable in a circumferential direction of the optical fiber (6), and, if a position of an intensity peak of the laser beam from the optical fiber (6) in an axial direction of the tubular body (2) is offset from the center of an irradiation profile, a position at which the optical fiber (6) is held in the circumferential direction is adjusted by the rotational hold mechanism (9) so as to eliminate the offset or to minimize an influence of the offset.

Abstract: An object is to provide a method and an apparatus for improving a residual stress in a tubular body, which are enabled to improve the residual stress reliably by clearly defining controlling rage for treatment conditions without depending on an installation state and configuration of the tubular body. When an outer-circumferential surface of a welded portion of a cylindrical tubular body (2) is irradiated with a laser beam that circles around an outer circumference of the tubular body (2), a heating width W in a circumferential direction heated by the laser-beam irradiation and a laser-beam moving speed V in the circumferential direction are set so that a stress in the circumferential direction in an inner surface of the tubular body (2) produced by the heating with the laser beam is at least larger than a yielding stress of a material that the tubular body (2) is made of.

Abstract: Disclosed are a laser processing apparatus and method that can effectively remove a low-k material formed on a wafer. A laser processing apparatus of the invention is a laser processing apparatus that processes a subject on which a low-k material is formed. The laser processing apparatus includes a laser generating unit that emits a laser beam; and an optical system that splits the laser beam emitted from the laser generating unit into two and irradiates the split laser beams onto the subject In this case, the optical system includes a pair of condensing lenses in which cut surfaces that are cut at a predetermined distance from central axes to be parallel to the central axes contact with each other, and the interval between the two split laser beams is the same as the interval between two edges of the low-k material in a removal subject region.

Abstract: There is provided a laser machining method and a laser machining apparatus whose machining accuracy and quality excel without lowering machining efficiency. One hole is machined by a split beam that is a first pulsed laser beam and another split beam that is a second pulsed laser beam whose irradiation position is determined based on irradiation position of the first laser beam. In this case, the machining quality may be improved by machining the circular hole by equalizing circling directions and angular velocity of the split beams. A beam splitter splits a laser beam outputted out of one laser oscillator into the split beams and AOMs can time-share them.

Abstract: A system and method for laser beam welding at least two adjacent superalloy components involves substantially simultaneous formation of a base weld with a first filler metal placed between the components and cap weld with second filler metal formed over the base weld. A shim is inserted between the components, which may optionally be formed with a groove along the joint surface. A filler wire is fed to a location over the given surface or within the optional groove. Two lasers or a laser and coupled beam splitter supply first and second laser beams that are applied at focal points separated by a predetermined distance (e.g., 0.05-1.5 cm). The first laser beam is used to form a base weld with the first filler metal between the components, and the second laser beam is used to form a cap weld with the second filler metal on top of the base weld.

Abstract: It is an object to achieve continuous crystal growth without optical interference using a compact laser irradiation apparatus. A megahertz laser beam is split and combined to crystallize a semiconductor film. At this point of time, an optical path difference is provided between the split beams to reduce optical interference. The optical path difference is set to have a length equivalent to the pulse width of the megahertz laser beam or more and less than a length equivalent to the pulse repetition interval; thus, optical interference can be suppressed with a very short optical path difference. Therefore, laser beams can be applied continuously and efficiently without energy deterioration.

Abstract: An annealing method irradiates a target object, having a film formed on its surface, with a laser beam to perform an annealing process to the target object. The surface of the target object is irradiated with the laser beam obliquely at an incident angle that is determined to achieve an improved laser absorptance of the film.

Abstract: A laser beam processing machine comprising a chuck table for holding a workpiece, a laser beam application means for applying a laser beam to the workpiece held on the chuck table, a processing feed means for moving the chuck table and the laser beam application means relative to each other in a processing-feed direction and an indexing-feed means for moving the chuck table and the laser beam application means in an indexing-feed direction perpendicular to the processing-feed direction, wherein the laser beam application means comprises a first laser beam application means for applying a first pulse laser beam having an energy density per one pulse of 20 to 60 J/cm2 and a second laser beam application means for applying a second pulse laser beam having an energy density per one pulse of 3 to 20 J/cm2.

Abstract: Disclosed are systems and methods for directing laser energy to surfaces of materials via elements which have sharp points, and for reducing the adverse effects of particles which become dislodged by scribing and laser machining of materials.

Abstract: A laser processing head mounted on a robot arm moves from with a constant speed in a direction from a welding point to a next welding point, while a reflection mirror continuously turns in order to maintain laser beams focused on the welding point until the welding at the welding point is completed, and the reflection mirror quickly turns to shift the focus of the laser beams onto the next welding point when the welding at the welding point is completed.

Abstract: The irradiation unevenness caused by drift occurring in a beam short-axis direction is reduced without adding a new beam shaping unit and affecting the propagation characteristic of a beam in an optical resonator. A position deviation detector for detecting a position deviation of a laser beam before passing through a beam shaping optical system, an angle deviation detector for detecting an angle deviation of the laser beam before passing through the beam shaping optical system, a deflection mirror for deflecting the laser beam, which is disposed in an optical path between a laser and an object (substrate), and a mirror controller for controlling orientation of the deflection mirror, based on detection data obtained using the position deviation detector and the angle deviation detector so as to eliminate the position deviation from a reference irradiation position in the short-axis direction of a linear beam on a surface to be irradiated.

Abstract: The present invention relates to a method and apparatus having a structure that enables laser processing of an object even when the object has a surface formed with irregularities. The laser processing method irradiates objects, each having a cylindrical form extending in a first direction, with laser light. Here, the objects are arranged on a first plane along a second direction orthogonal to the first direction. The arranged objects are irradiated with first and second laser light beams in irradiation directions different from each other to the first plane. At least during when the first and second irradiation light beams are respectively emitted, irradiation positions of the first and second laser light beams to the first plane are relatively moved.

Abstract: A method of directing a pulse of laser energy though a workpiece. The workpiece has: a substrate that transmits the laser energy; focusing elements on a surface of the substrate proximal to the laser that focus the laser energy; and a coating on the substrate distal to the laser that absorbs a portion of the laser energy. Each focusing element focuses the laser energy to a point that removes or ablates a portion of the coating from the substrate to produce a hole in the coating.

Abstract: Laser-based methods of stripping different types of fiber optic cables (100) are disclosed. The method includes directing a focused laser beam (202) onto the cable's protective cover (114). The method also includes moving the fiber optic cable relative to the focused laser beam in a direction substantially along a central axis (AC) to form a substantially axially oriented groove (250) in the protective cover, wherein the groove does not reach one or more optical fibers (110) carried by the cable. The method can further include opening the protective cover at the groove to form a split protective cover portion (114S), and removing the split protective cover portion from the fiber optic cable. Methods of stripping a cable by forming two grooves in the protective cover using two focused laser beams are also disclosed.

Abstract: A laser processing machine having a laser beam irradiation unit is provided. The laser beam irradiation unit includes: a laser beam oscillation section; a beam splitter adapted to split the laser beam emitted from the laser beam oscillation section into a first laser beam and a second laser beam; a condenser lens adapted to condense the first and second laser beams; a prism adapted to lead the first and second laser beams split by the beam splitter to the condenser lens; a first angle-changing mirror disposed on a first optical path adapted to lead the first laser beam split by the beam splitter; a second angle-changing mirror disposed on a second optical path adapted to lead the second laser beam split by the beam splitter to the prism; and a half-wave plate disposed in the first or second optical path to allow one of respective directions of the first and second polarization planes to be aligned with the other.

Abstract: In laser micromachining and laser defect repair of a first material, a first set of one or more laser wavelengths is selected in accordance with the first material's absorption characteristics and is combined and delivered concurrently with a second set of one or more laser wavelengths which is selected in accordance with the absorption characteristics of a second material generated by and remaining from the ablating interaction of the first material with the first set of laser wavelengths. The concurrent presence of the second set of one or more laser wavelengths removes the residual second material.

Abstract: A system for delivering energy to a substrate includes a laser energy source providing a plurality of laser beams, wherein each of the beams is steered to an independently selectable location on a target, and is independently focused onto the target.

Abstract: The present invention is directed to an arrangement for forming one or more separated scores in a surface of a substrate. The arrangement comprises a laser for providing a laser beam, optical guiding means for guiding said laser beam to said surface of said substrate, means for moving said substrate relative to said laser beam in at least one cutting direction for forming said scores, and primary splitting means for splitting said laser beam into a plurality of primary cutting beams for forming said scores parallel to each other. Said primary splitting means are arranged for moving said primary cutting beams relative to each other for adjusting the separation between said parallel scores. The invention is further related to a method for forming one or more separated scores in a surface of a substrate.

Abstract: The present invention, among other things, relates to an apparatus (10) for working a surface (11) of a workpiece, in particular a metal workpiece, by means of laser radiation. The apparatus (10) is characterized by a scanner device (20), which is mounted in a rotationally immovable manner in the working apparatus (10) and is intended for shaping a laser beam that is to be deflected and positioned onto the surface to be worked, a control device for changing the orientation of the scanning direction of the laser beam shaped in the scanner device (20), and an optics element (40), which is movable about an axis of rotation (12), is arranged downstream of the scanner device (20) in the beaming direction of the laser beam and advantageously has a beam splitter device for splitting the laser beam into two or more beam parts (41, 42) and for deflecting and positioning the beam parts (41, 42) onto the surface (11) that is to be worked.

Abstract: System and method of photoaltering a material. The system includes a laser source operable to produce a primary pulsed beam, a holographic optical element configured to receive the primary pulsed beam and transmit a plurality of secondary beams, and a scanner operable to direct the secondary beams to the material. The secondary beams are based on the primary pulsed beam. The method includes phase shifting a pulsed laser beam to produce an input beam, holographically altering the input beam to produce a plurality of transmission beams, and scanning a portion of the material with the transmission beams.

Abstract: A Plate polarising beam splitter 22 splits an incident laser beam 21 to form a first laser beam 24 and a second laser beam 25. The first laser beam is optically modified using an arcuate reflector 23 so that the first laser beam has a different divergence or convergence from that of the second laser beam. The first laser beam 24 is focussed at a first focus 27 on an optical axis of a focussing lens 26 and the second laser beam is focussed at a second focus 28 on the optical axis for machining a workpiece. The apparatus is suitable for machining with the laser beams steered by a galvanometer scanner.

Abstract: The invention provides a method of making a component from first and second parts which are joined in a welding process wherein a laser beam is transmitted in a direction from a laser source and at least partly into a gap. The gap is made between edges of the component, and to enable a faster laser welding process, the laser has a focus point size which is at least of the size of the gap. To enable better control of the width of the gap, the invention further provides a method and components wherein one part is formed with a neck which extends into a complementary socket of the other part to prepare the parts for the welding process. The invention in particular concerns welding of brass.

Abstract: A method for laser drilling of holes in a substrate (44) with varying simultaneity including operating a laser (22) to produce a single output beam (24) whose pulses have a total energy, dividing the single output beam into plural beams (41) to an extent which varies over time and applying the plural beams to plural hole drilling locations (209, 210, 212, 214, 216, 218, 220, 222) on the substrate including simultaneously drilling first parts of multiple holes using corresponding ones of the plural beams having a pulse energy which is a first fraction of the total energy and thereafter drilling at least one second part of at least one of the multiple holes using at least one of the plural beams each having a pulse energy which is at least a second fraction of the total energy, the second fraction being different from the first fraction.

Abstract: In a manufacturing process of a semiconductor device, a manufacturing technique of a semiconductor device by which a lithography step that uses a photoresist is simplified is provided. A manufacturing cost is reduced and throughput is improved. An irradiation object is formed over a substrate by sequentially stacking a first material layer and a second material layer. The irradiation object is irradiated with a first laser beam that is absorbed by the first material layer and a second laser beam that is absorbed by the second material layer so that the laser beams overlap. A part or all of the region irradiated with an overlap part of the laser beams is ablated to form an opening.

Abstract: A laser beam processing machine comprising a chuck table for holding a workpiece, a laser beam application device for applying a laser beam to the workpiece held on the chuck table, a processing-feed device for moving the chuck table and the laser beam application device relative to each other in a processing-feed direction (X-axis direction), and an indexing-feed device for moving the chuck table and the laser beam application device relative to each other in an indexing-feed direction (Y-axis direction) perpendicular to the processing-feed direction (X-axis direction), wherein the laser beam application device includes a laser oscillation device for oscillating a laser beam, a first acousto-optic deflection device for deflecting the optical axis of a laser beam oscillated by the laser beam oscillation device in the processing-feed direction (X-axis direction), and a second acousto-optic deflection device for deflecting the optical axis of a laser beam oscillated by the laser beam oscillation device in the i

Abstract: Disclosed herein is an apparatus for cutting a glass plate. The apparatus comprises a cracking means for forming a minute crack at a point on the glass plate where the cutting is started, at least one scribing means using a laser beam absorbed by the glass plate, at least one quenching means using a quenching fluid after irradiation of the laser beam, a breaking means using the laser beam. The breaking means comprises a laser oscillator, a reflection mirror and a focusing lens. The focusing lens has at least two or more focal lengths. The apparatus may further apparatus further comprise a photo mask formed with light transmission openings for transmitting a part of the laser beam to be irradiated on the glass plate instead of the focusing lens. With the apparatus of the present invention, the problems caused by the conventional lens, such as a reduced straightness of a cutting line or a rough cutting plane, can be prevented, thereby providing a clean cutting plane.

Abstract: A laser annealing apparatus used in a crystallization process of an amorphous silicon thin film. The laser annealing apparatus includes a laser beam generation unit generating a laser beam, an optical system dividing the laser beam into a plurality of linear laser beams and including a focusing lens focusing the linear laser beams and projecting the focused linear laser beam on a substrate to be processed, and a focusing lens adjustment device adjusting a perpendicular distance and a rotation angle of the focusing lens relative to the substrate.

Abstract: A system for delivering energy to a substrate includes a laser energy source providing a plurality of laser beams, wherein each of the beams is steered to an independently selectable location on a target, and is independently focused onto the target.

Abstract: A system for delivering energy to a substrate including a dynamically directable source of radiant energy providing a plurality of beams of radiation, each propagating in a dynamically selectable direction. Independently positionable beam steering elements in a plurality of beam steering elements are operative to receive the beams and direct them to selectable locations on the substrate.

Abstract: A laser processing apparatus is provided including: a laser generator generating a light beam; a branching means for branching out the light beam to a plurality of beams arranged at equal intervals; a shifting means for shifting the plurality of beams at a pitch equal to a multiple of natural number of the arranged intervals relatively over a target; and a control means for controlling the intensity of the beam synchronously with the shifting pitch of the plurality of beams.

Abstract: A laser machining apparatus in which three or more beam splits are made incident on one machining lens so that high speed machining can be achieved, and the machining quality (shapes, dimensions, accuracy and straightness of machined holes) is excellent. The optical paths of beams A and B having the same polarization direction are aligned almost in one and the same direction by a total reflection/transmission type beam combining means 31c using a difference in incident angle. After that, the optical paths of the beams A and B and the optical path of a beam C different in polarization direction therefrom are aligned almost in one and the same direction by a polarizing type beam combining means 32. Then, the beams A, B and C are made incident on a machining lens 45.

Abstract: A plurality of configurations is simultaneously formed in a material by a single laser beam having a desired distribution pattern of wavelengths. An input laser beam has an initial wavelength distribution pattern. The initial wavelength distribution pattern is adjusted or modified into a desired final wavelength distribution pattern. For example, the initial wavelength distribution pattern is a wide range of wavelengths in a single bell-curve distribution while the desired final wavelength distribution pattern has a specific number of sharp peaks each over a predetermined narrow range. The laser beam having the desired final wavelength distribution pattern is focused upon on a material. Because of the multiple peaks in the wavelength distribution, the laser beam is focused at a plurality of the focal distances. A number of structures is simultaneously formed in a material at the multiple focal points or at multiple locations/depths when the above laser beam is projected onto the material.

Abstract: A laser beam processing machine comprising a chuck table for holding a workpiece, a laser beam application means for applying a laser beam capable of passing through the workpiece to the workpiece held on the chuck table, and a processing-feed means for moving the chuck table and the laser beam application means relative to each other, the laser beam application means comprising a laser beam oscillation means, an optical transmission means for transmitting a laser beam oscillated by the laser beam oscillation means, and a transmitting/converging means having a single condenser lens for converging laser beams transmitted by the optical transmission means, wherein the transmitting/converging means converges a laser beam oscillated from the laser beam oscillation means at two or more focusing points which are displaced in the direction of the optical axis and the processing-feed direction through the single condenser lens.

Abstract: A laser processing machine having a laser beam irradiation unit is provided. The laser beam irradiation unit includes: a laser beam oscillation section; a beam splitter adapted to split the laser beam emitted from the laser beam oscillation section into a first laser beam and a second laser beam; a condenser lens adapted to condense the first and second laser beams; a prism adapted to lead the first and second laser beams split by the beam splitter to the condenser lens; a first angle-changing mirror disposed on a first optical path adapted to lead the first laser beam split by the beam splitter; a second angle-changing mirror disposed on a second optical path adapted to lead the second laser beam split by the beam splitter to the prism; and a half-wave plate disposed in the first or second optical path to allow one of respective directions of the first and second polarization planes to be aligned with the other.

Abstract: A laser processing machine includes a beam splitter for splitting an incoming laser beam into a first laser beam having a first intensity and a second laser beam having a second intensity, a first focusing mirror for focusing the first laser beam onto a first laser processing site on a workpiece at an angle from a direction directly above the workpiece, a second focusing mirror for focusing the second laser beam onto second laser processing site on the workpiece at an angle from a direction directly above the workpiece, and a supplementary laser processing element for supplementing laser processing of the workpiece, wherein the supplementary laser processing element is disposed directly above the first or second laser processing site.

Abstract: A laser-welding apparatus may include a laser source, an incoming laser beam produced by the laser source, and a beam splitter that splits the incoming laser beam to form a leading beam and a trailing beam. A first focusing lens may focus the leading beam and a second focusing lens may focus the trailing beam to form a trailing-beam pattern on a workpiece. The trailing-beam pattern may include a crescent-shape having arms and a tail portion.

Abstract: Providing a method and apparatus for efficiently irradiating a uniform laser light on an irradiation surface even when a laser light of high coherence or a large size substrate is used. The laser irradiation apparatus of the invention comprises a laser; means for dividing a laser light emitted from the laser into plural laser beams; means for synthesizing the laser beams on the irradiation surface or place in the vicinity thereof thereby forming a laser light having a periodical energy distribution; and means for moving the substrate relative to the laser light. Such a laser irradiation apparatus may be used to anneal the overall surface of a semiconductor film.

Abstract: Multiple laser beams selectively irradiate electrically conductive structures on or within a semiconductor substrate. The structures are arranged in a plurality of substantially parallel rows extending in a generally lengthwise direction. One method propagates first and second laser beams along respective first and second propagation paths having respective first and second axes incident at respective first and second locations on or within the semiconductor substrate at a given time. The first and second locations are either on a structure in their respective rows or between two adjacent structures in their respective rows, which are distinct. The second location is offset from the first location by some amount in the lengthwise direction of the rows. The method moves the laser beam axes substantially in unison in the lengthwise direction of the rows relative to the semiconductor substrate, so as to selectively irradiate structures in the rows with the laser beams.

Abstract: Disclosed herein is a processing apparatus using a laser beam, which includes a holder for holding a workpiece, and laser beam applicator for irradiating the workpiece, held by the holder, with a pulsed laser beam capable of passing through the workpiece, thereby deteriorating the workpiece. The laser beam applicator includes a pulsed laser beam oscillator and a transmitter/focuser for transmitting and focusing the pulsed laser beam oscillated by the pulsed laser beam oscillator. The transmitter/focuser focuses the pulsed laser beam, with a time difference provided, to at least two focus points that are displaced in the optical axis direction.

Abstract: A method of laser machining a fluid slot includes directing a UV laser beam towards a substrate with microelectronics to form a slot through the substrate.

Abstract: The present invention relates to a method and apparatus having a structure that enables laser processing of an object even when the object has a surface formed with irregularities. The laser processing method irradiates objects, each having a cylindrical form extending in a first direction, with laser light. Here, the objects are arranged on a first plane along a second direction orthogonal to the first direction. The arranged objects are irradiated with first and second laser light beams in irradiation directions different from each other to the first plane. At least during when the first and second irradiation light beams are respectively emitted, irradiation positions of the first and second laser light beams to the first plane are relatively moved.

Abstract: A device for material processing, such as welding, joining, cutting, inspecting and the like, includes an energy beam source and one or more energy beam transfer devices. The one or more transfer devices may direct an energy beam at one or more predetermined locations on a workpiece. In one embodiment of the present invention, the transfer device may be rotated around or moved relative to the workpiece on a movable frame. In another embodiment of the present invention, an inspection device may be moved or rotated around a workpiece on a movable frame. A further material processing device may include a material processing system directed along a predetermined path. The material processing device may also include an inspection system adapted to move along the predetermined path.

Abstract: A multi-axis laser machine in which the working efficiency can be improved even when machining positions in respective systems are different from each other. The positioning operation of a laser positioning unit for positioning an optical path of a laser beam in an axis and the positioning operation of another laser positioning unit for positioning another optical path of the laser beam in another axis are performed independently of each other. An arbitration unit monitors the laser positioning units as to whether they have finished positioning or not. The arbitration unit operates a deflection unit (AOM) so as to supply the laser beam to one of the laser positioning units which has finished positioning. Incidentally, when the laser positioning units finish positioning simultaneously, the arbitration unit supplies the laser beam to the laser positioning units in a predetermined sequence.

Abstract: A system for delivering energy to a substrate includes a laser energy source providing at least two laser beams, wherein each of the beams is steered to an independently selectable location on a target, and is independently focused onto the target.

Abstract: A method is proposed for preparing a structured metallic surface of a body or for the structuring close to the surface or the generation of metallic structures, first of all on a first metal layer or on a first intermetallic layer a second metal layer or a second intermetallic layer, the second layers differing from the first layers, being generated; and thereafter at least the second metal layer or the second intermetallic layer being heated up region by region in such a way that, in that location, there is formed an intermetallic compound using the material of the first intermetallic layer or the first metal layer and the material of the second metal layer or the second intermetallic layer, into which surface regions are embedded, which are at least essentially made of the material of the second metal layer or the second intermetallic layer.

Abstract: A laser material processing apparatus for processing a workpiece (22) in such a way as to separate one laser light (26) into two laser beams (26a, 26b) via first polarizer (25), one laser beam being passed via the mirrors (24), the other laser beam being scanned biaxially by a first galvano scanner (29), and conduct two laser beams (26a, 26b) to a second polarizer (27) for scanning via a second galvano scanner (30), wherein an optical path is constituted such that the laser beam (26b) transmitted through the first polarizer (25) is reflected by the second polarizer (27), and the laser beam (26a) reflected by the first polarizer (25) is transmitted through the second polarizer (27).

Abstract: The invention relates to a method for putting color to glass. This method includes the steps of (a) introducing a laser beam into an interferometer such that the laser beam is split into at least first and second laser beams in the interferometer and that the at least first and second laser beams come out of the interferometer; and (b) irradiating a glass with the at least first and second laser beams to write a plurality of lines simultaneously on a surface of the glass and/or in an inside of the glass.

Abstract: A method and apparatus for manufacturing patterns on a reticle blank comprising a substrate made from material transparent to UV irradiation and having a first surface and a second opposite surface, the first surface coated with a chrome layer. The method comprises providing ultra-short pulsed laser beams, focusing means, relative displacement facilitator for facilitating relative displacement of the reticle blank relative to said at least one of a plurality of target locations, and a controller for controlling the synchronization and operation of the laser beam source, the focusing means and the relative displacement facilitator. Ultra-short pulsed laser beam is irradiated in a predetermined pattern directed at the second surface and passing through the substrate, focused on the chrome layer or on its proximity.

Abstract: Provided is a multi-beam laser drilling apparatus for drilling a workpiece, simultaneously at two positions while telecentric errors are suppressed, in which a conventional optical system in which galvanometer mirrors are used for a first laser beam, and a galvanometer-mirror system is located close to an f? lens in order to prevent occurrence of telecentric error. A second laser beam which has been deflected by a second galvanometer-mirror system, transmits through a polarized beam mixers and is incident upon the first galvanometer-mirror system and the f? lens, and accordingly, the workpiece is drilled simultaneously at two positions with the use of both first and second laser beams.