US 11,850,679 B2
Laser processing apparatus and method
Jarno Kangastupa, Tampere (FI); and Arto Salokatve, Tampere (FI)
Assigned to Corelase Oy, Tampere (FI)
Appl. No. 16/763,237
Filed by Corelase Oy, Tampere (FI)
PCT Filed Dec. 29, 2017, PCT No. PCT/FI2017/050959
§ 371(c)(1), (2) Date May 12, 2020,
PCT Pub. No. WO2019/129917, PCT Pub. Date Jul. 4, 2019.
Prior Publication US 2020/0306878 A1, Oct. 1, 2020
Int. Cl. B23K 26/06 (2014.01); B23K 26/073 (2006.01); B23K 26/24 (2014.01); B23K 26/70 (2014.01); B23K 103/10 (2006.01); B23K 101/18 (2006.01)
CPC B23K 26/0604 (2013.01) [B23K 26/0734 (2013.01); B23K 26/24 (2013.01); B23K 26/0648 (2013.01); B23K 26/705 (2015.10); B23K 2101/18 (2018.08); B23K 2103/10 (2018.08)] 15 Claims
OG exemplary drawing
 
1. A laser welding apparatus comprising:
at least one first laser device, each first laser device providing at least one first optical feed fiber for delivering a first laser beam;
at least one second laser device, each second laser device providing at least one second optical feed fiber for delivering a second laser beam; and
a beam combiner connected to said at least one first and said at least one second optical feed fibers and to a multi-core optical fiber, said multi-core optical fiber having a first core with a circular cross-section located in a center of the multi-core optical fiber and a second core with an annular cross-section spaced from and concentric to the first core, wherein said at least one first optical feed fiber is aligned with the first core of said multi-core optical fiber, and wherein said at least one second optical feed fiber is aligned between an inner diameter and an outer diameter of said annular second core of said multi-core optical fiber;
said first and second cores being connectable to a laser processing head having a focusing lens to image a composite laser beam comprising a first output laser beam and a second, independent output laser beam to a workpiece to be welded wherein the first output laser beam has a circular cross-section and the second output laser beam has an annular cross-section concentric to and spaced apart from the first output laser beam at the workpiece, wherein
the second laser device is a fiber laser device or a fiber-coupled laser device,
the laser welding apparatus is configured to form the second output laser beam at least on the basis of the second laser beam, and
the second output laser beam comprises a first wavelength and a second wavelength, the first and second wavelengths being generated by different laser sources, the difference between the first wavelength and the second wavelength being at least 15 nanometers, such that an effective focal length of the focusing lens causes a focal shift of at least 0.1 millimeters between images associated with the first wavelength and the second wavelength.