# US 2021/0276128 A1 · Butt welding with ultrashort pulse laser beams, and optical elements joined together from individual parts > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2021/0276128 A1 - Document ID: US20210276128A1 - Status: Published application - Kind: A1 - Application number: 17/331,093 - Filed: 2021-05-26 - Published: 2021-09-09 - Earliest claimed: 2018-11-28 - Assignees: Trumpf Laser GmbH - Applicants: Trumpf Laser GmbH - Inventors: Dominik Bauer; Helge Höck; Michael Scharun; Manuel Schindler - Web page: https://patentgrep.com/patent/US20210276128A1 ## CPC - B23K 26/26: of rectilinear seams - C03B 23/203: Uniting glass sheets (C03B23/24 takes precedence) - B23K 26/0624: {using ultrashort pulses, i.e. pulses of 1 ns or less} - B23K 26/0876: {in at least two axial directions} - B23K 26/324: involving non-metallic parts - B23K 2103/54: {Glass} - B23K: SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM - C03B: MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES ## Abstract The present disclosure provides methods, devices, and systems for the butt welding of two, e.g., planar, workpieces composed of glass, e.g., quartz glass, by a pulsed laser beam, e.g., an ultrashort pulse (“USP”) laser beam, which is directed into the workpiece material parallel to the joining surface of the two workpieces and which is focused into the workpiece material in the region of the joining surface to locally melt the two workpieces in the region of their joining surface, wherein the laser focus of the laser beam focused into the workpiece material is moved in or counter to the beam direction of the laser beam to produce in the region of the joining surface a weld seam extending along the beam direction. ## Claims ### Claim 1 A method for butt welding two workpieces composed of glass, the method comprising: focusing at least one ultrashort pulse laser beam into the two workpieces parallel to a joining surface of the two workpieces and focusing the at least one ultrashort pulse laser beam into a region of the joining surface to locally melt the two workpieces in the region of their joining surface; and moving a laser focus of the ultrashort pulsed laser beam in or counter to a beam direction of the laser beam to produce in the region of the joining surface a weld seam extending along the beam direction. ### Claim 2 (depends on 1) The method of claim 1, further comprising moving surfaces of the two workpieces to be joined into contact along the joining surface. ### Claim 3 (depends on 1) The method of claim 1, wherein the movement of the laser focus in or counter to the beam direction is effected continuously or step-by-step. ### Claim 4 (depends on 3) The method of claim 3, wherein the movement of the laser focus in or counter to the beam direction is effected continuously at an advance speed of 0.5 mm/s to 100 mm/s. ### Claim 5 (depends on 3) The method of claim 3, wherein the movement of the laser focus in or counter to the beam direction is effected continuously at an advance speed of 5 mm/s to 30 mm/s. ### Claim 6 (depends on 3) The method of claim 3, wherein the movement of the laser focus in or counter to the beam direction is effected continuously at an advance speed of 20 mm/s. ### Claim 7 (depends on 1) The method of claim 1, wherein the weld seam has a seam diameter of 5 to 500 μm. ### Claim 8 (depends on 1) The method of claim 1, wherein the weld seam has a seam diameter of 50 to 100 μm. ### Claim 9 (depends on 1) The method of claim 1, wherein a transverse movement of the laser focus is also superimposed on the advance movement of the laser focus in or counter to the radiation direction of the laser beam. ### Claim 10 (depends on 1) The method of claim 1, wherein the ultrashort pulsed laser beam comprises a laser pulse packet consisting of individual pulses. ### Claim 11 (depends on 10) The method of claim 10, wherein the individual pulses in the pulse packet are identical. ### Claim 12 (depends on 1) The method of claim 1, wherein the laser beam impinges at right angles or obliquely on a workpiece side facing the laser beam. ### Claim 13 (depends on 1) The method of claim 1, wherein a plurality of weld seams are produced at a distance from one another along a joining line of the two workpieces. ### Claim 14 (depends on 1) The method of claim 1, wherein during the movement of the laser focus in or counter to the beam direction, the laser beam is not moved relative to the two workpieces. ### Claim 15 (depends on 1) The method of claim 1, wherein during the advance movement of the laser focus in or counter to the beam direction, the laser beam is moved relative to the two workpieces parallel or transversely with respect to a joining line of the two workpieces. ### Claim 16 (depends on 15) The method of claim 15, wherein a focus speed at which the laser focus is moved in or counter to the beam direction is greater than an advance speed at which the laser beam is moved parallel or transversely with respect to the joining line. ### Claim 16 (depends on 1) The method of claim 1, wherein the pulsed laser beam comprises laser radiation having pulse durations of less than 50 ps. ### Claim 17 An optical element composed of glass, comprising two individual parts that are laser-welded to one another, wherein the two individual parts are laser-welded to one another by at least one weld seam extending in a thickness direction of the two individual parts. ### Claim 18 (depends on 17) The optical element of claim 17, wherein the weld seam extends at right angles or obliquely with respect to a surface of the optical element. ### Claim 19 (depends on 17) The optical element of claim 17, wherein the weld seam has a length of at least 50 μm. ### Claim 20 (depends on 17) The optical element of claim 17, wherein the weld seam is a continuous line or a repeatedly interrupted line. ### Claim 21 (depends on 17) The optical element of claim 17, wherein a plurality of weld seams extending in the thickness direction of the two individual parts are arranged at a distance from one another along the joining line of the two individual parts. ### Claim 22 (depends on 17) The optical element of claim 17, wherein the weld seam has a seam diameter of 5 to 500 μm.