Granted Patent B2

US 12,447,553 · App. 18/505,630 · Granted Oct 21, 2025

Inventors: Jarno Kangastupa (Tampere, FI); Arto Salokatve (Tampere, FI)

Assignee: Corelase Oy

B23K26/0604B23K26/0734B23K26/24B23K26/0648B23K26/705B23K2101/18B23K2103/10

Abstract

Claims (15)

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.

2. The apparatus of claim 1 wherein the second laser device and the third laser device are one of a fiber laser device or a fiber-coupled laser device.

3. The apparatus of claim 2 wherein the first laser device is a fiber laser device.

4. The apparatus of claim 1 further including a control unit functionally connected to the first, second and third laser devices to individually control the power density reaching the workpiece of first, second, and third laser beams.

5. The apparatus of claim 1 wherein there is annular region in the image of the composite laser beam between the circular first laser beam and the annular second and third laser beams, wherein the annular region carries only stray or no laser radiation.

6. The apparatus of claim 1 wherein the processing head is arranged for spot welding.

7. The apparatus of claim 1 wherein the processing head is arranged for continuous welding.

8. The apparatus of claim 1 wherein the laser beams generated by the first, second, and third laser devices are each coupled to respective first, second, and third feed fibers for delivery to the optical fiber.

9. The apparatus of claim 8 wherein the first, second, and third feed fibers are arranged within a beam combiner and wherein the beam combiner is fused to the optical fiber.

10. The apparatus of claim 1 wherein the processing head further includes a gas jet to supply pressurized gas to the workpiece.

Assignments (1)

Continuity (2)

References Cited (175)