US 12,447,553 B2
Laser processing apparatus and method
Jarno Kangastupa, Tampere (FI); and Arto Salokatve, Tampere (FI)
Assigned to Corelase Oy, Tampere (FI)
Filed by Corelase Oy, Tampere (FI)
Filed on Nov. 9, 2023, as Appl. No. 18/505,630.
Application 18/505,630 is a continuation of application No. 16/763,237, granted, now 11,850,679, previously published as PCT/FI2017/050959, filed on Dec. 29, 2017.
Prior Publication US 2024/0082948 A1, Mar. 14, 2024
Int. Cl. B23K 26/06 (2014.01); B23K 26/073 (2006.01); B23K 26/24 (2014.01); B23K 26/70 (2014.01); B23K 101/18 (2006.01); B23K 103/10 (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)] 10 Claims
OG exemplary drawing
 
1. An apparatus comprising;
a first laser device generating a first laser beam having a first wavelength;
a second laser device generating a second laser beam having a second wavelength;
a third laser device generating a third laser beam having a third wavelength, wherein the difference between the second wavelength and the third wavelength is at least 15 nanometers;
an optical fiber, said optical fiber having a center core surrounded by a first annular cladding, said optical fiber further including an annular core surrounding the first annular cladding, said optical fiber further including a second cladding surrounding the annular core and wherein the first laser beam is coupled into the center core of the optical fiber and wherein the second and third laser beams are coupled into the annular core of the optical fiber; and
a laser processing head arranged to receive the first, second and third laser beams exiting the optical fiber, said laser processing head having a focusing lens to image a composite laser beam, including the first, second, and third laser beams, to a workpiece wherein the first laser beam has a circular cross-section at the workpiece and the second and third laser beams have an annular cross-section concentric to and spaced apart from the first laser beam at the workpiece, wherein the difference between the second and third wavelengths coupled with the effective focal length of the focusing lens causes a focal shift of at least 0.1 millimeters between images associated with the second laser beam and third laser beam on the workpiece.