Optical arrangement and laser system

Patent metadata

Field	Value
Publication number	US-12235462-B2
Application number	US-202217956843-A
Country	US
Kind code	B2
Filing date	Sep 30, 2022
Priority date	Mar 30, 2020
Publication date	Feb 25, 2025
Grant date	Feb 25, 2025

Abstract

An optical arrangement converts a laser beam into a line-type beam having a line-type beam cross-section that extends along a line direction with a non-vanishing intensity. The arrangement has: reshaping optics having: an input aperture through which the laser beam is radiated in; and an elongate output aperture, the reshaping optics being configured such that the laser beam radiated in is converted into a beam packet with beam segments that emerge through the output aperture; homogenization optics, which contribute to the conversion of the beam packet into the line-type output beam, and by which different beam segments are mixed and superposed along the line direction; and redirection optics configured to redirect the laser beam such that an incidence position/direction of laser beam on the input aperture is changed in dependence on time.

First claim

The invention claimed is:

1. An optical arrangement for converting at least one input laser beam into a line-type output beam, which propagates along a propagation direction and which has, in a working plane, a line-type beam cross-section that extends along a line direction with a non-vanishing intensity, the optical arrangement comprising:
a reshaping optical unit having an input aperture through which the at least one input laser beam is capable of being radiated in, and an elongate output aperture, wherein the reshaping optical unit is configured such that the input laser beam radiated in through the input aperture is converted into a beam packet having a multiplicity of beam segments that emerge through the output aperture, wherein adjacent beam segments of the input laser beam, when passing through the reshaping optical unit, are rearranged into the multiplicity of beam segments of the beam packet, wherein adjacent beam segments of the beam packet have traveled along optical path lengths when passing through the reshaping optical unit that differ from each other such that the beam packet is spatially incoherent;
a homogenization optical unit disposed downstream from the reshaping optical unit, wherein the homogenization optical unit contributes to the conversion of the beam packet into the line-type output beam, and wherein different beam segments, of the multiplicity of beam segments of the beam packet, after passing through the homogenization optical unit, are mixed and superposed along the line direction; and
a redirection optical unit disposed upstream from the reshaping optical unit, wherein the redirection optical unit is configured to redirect the at least one input laser beam into the reshaping optical unit through the input aperture in such a way that an incidence position or an incidence direction of the at least one input laser beam on the input aperture of the reshaping optical unit is changed in dependence on time, so that an angle distribution of the output beam is changed in dependence on time or an angle distribution of the beam packet emerging from the output aperture of the reshaping optical unit is changed in dependence of time.

2. The optical arrangement as claimed in claim 1 , wherein the redirection optical unit is configured to change the incidence position or the incidence direction of the input laser beam on the input aperture in a periodic or non-periodic recurring movement pattern.

3. The optical arrangement as claimed in claim 1 , wherein the redirection optical unit is configured to change the incidence position of the input laser beam along an input aperture longitudinal direction.

4. The optical arrangement as claimed in claim 3 , wherein the redirection optical unit is configured to shift the incidence position of the input laser beam back and forth along the input aperture longitudinal direction.

5. The optical arrangement as claimed in claim 1 , wherein the redirection optical unit is configured to change the incidence direction of the input laser beam such that a plane containing the incidence direction and an input aperture longitudinal direction is pivoted around the input aperture longitudinal direction.

6. The optical arrangement as claimed in claim 1 , wherein the redirection optical unit comprises at least one mirror device, wherein the at least one mirror device comprises at least one shiftable or tiltable mirror.

7. The optical arrangement as claimed in claim 6 , wherein the at least one mirror device comprises two mirrors which are shiftable or tiltable relative to one another.

8. The optical arrangement as claimed in claim 1 , wherein the redirection optical unit comprises a lens system with a first lens and a second lens, wherein the second lens is shiftable or tiltable relative to the first lens.

9. The optical arrangement as claimed in claim 1 , wherein the redirection optical unit comprises at least one optical element which is rotatably mounted.

10. The optical arrangement as claimed in claim 1 , wherein the redirection optical unit is arranged on a first foundation, wherein the reshaping optical unit is arranged on a second foundation, and wherein the first foundation and the second foundation are arranged separately from each other.

11. The optical arrangement as claimed in claim 1 , further comprising a Fourier lens arranged downstream of the homogenization optical unit in the beam path.

12. The optical arrangement as claimed in claim 1 , wherein the input aperture of the reshaping optical unit is elongate and extends longitudinally along an input aperture longitudinal direction, wherein the output aperture is elongate and extends along an output aperture longitudinal direction, which differs from the input aperture longitudinal direction.

13. The optical arrangement as claimed in claim 12 , wherein the reshaping optical unit is configured in such a way that a distance between adjacent beam segments of the beam packet is greater than an extent of the beam segments perpendicular to the output aperture longitudinal direction and perpendicular to the propagation direction.

14. The optical arrangement as claimed in claim 1 , wherein the reshaping optical unit is formed from a monolithic, plate-type, transparent material, having a plate front side and a plate rear side extending substantially parallel thereto, wherein a region of the plate front side provides the input aperture and a region of the plate rear side provides the output aperture, wherein the reshaping optical unit is configured in such a way that, after input coupling through the input aperture, the beam segments of the input laser beam are guided by reflection at the plate front side and at the plate rear side to the output aperture.

15. The optical arrangement as claimed in claim 1 , wherein the homogenization optical unit comprises at least one lens array which has a multiplicity of cylindrical lenses, and wherein the cylindrical lenses are geometrically dimensioned in such a way that the beam packet passes through a multiplicity of adjacent cylindrical lenses.

16. A laser system for generating the line-type output beam with an intensity distribution which has a line-type intensity profile in the beam cross section, the laser system comprising:
at least one laser light source configured to output the at least one input laser beam; and
the optical arrangement as claimed in claim 1 for converting the at least one input laser beam into the line-type output beam.

Assignees

• Trumpf Laser & Systemtechnik Gmbh

Inventors

• Zeller Thomas
• Tillkorn Christoph
• Hellstern Julian
• Heimes Andreas
• Lingel Christian
• Irion Christoph
• Jenne Michael

Classifications

• G02B27/0927 Primary

  Systems for changing the beam intensity distribution, e.g. Gaussian to top-hat · CPC title

• B23K26/0648

  comprising lenses · CPC title

• B23K26/0652

  comprising prisms · CPC title

• B23K26/0738

  into a linear shape · CPC title

• G02B27/126

  The splitting element being a prism or prismatic array, including systems based on total internal reflection · CPC title