Optical arrangement and laser system

Patent metadata

Field	Value
Publication number	US-11536979-B2
Application number	US-201917253664-A
Country	US
Kind code	B2
Filing date	Jun 5, 2019
Priority date	Jun 22, 2018
Publication date	Dec 27, 2022
Grant date	Dec 27, 2022

Abstract

An optical arrangement converts an input laser beam into a line-like output beam, which propagates along a propagation direction and which has, in a working plane, a line-like beam cross section extending along a line direction. The optical system includes: a reshaping optical unit having an input aperture, through which the input laser beam is radiated, and an elongate output aperture, elongatedly extending along an aperture longitudinal direction, the reshaping optical unit converting the input laser beam radiated through the input aperture into a beam packet exiting through the output aperture; and a homogenization optical unit which converts the beam packet into the line-like output beam, different beam segments of the beam packet being intermixed and superimposed along the line direction. The aperture longitudinal direction extends in a manner rotated about the propagation direction by a non-vanishing angle of rotation with respect to the line direction.

First claim

The invention claimed is:

1. An optical arrangement for converting an input laser beam into a line-like output beam, which propagates along a direction of propagation and which has, in a working plane, a line-like beam cross section of non-vanishing intensity that extends along a direction of a line, the optical system comprising:
a reshaping optical unit having an input aperture, through which the input laser beam can be radiated, and an elongate output aperture, which extends along an aperture longitudinal direction in an elongate manner, the reshaping optical unit being configured wherein the input laser beam radiated through the input aperture is converted into a beam packet exiting through the output aperture; and
a homogenization optical unit which is designed to convert the beam packet into the line-like output beam, different beam segments of the beam packet being intermixed and superimposed along the direction of the line, wherein the aperture longitudinal direction extends in a manner rotated about the direction of propagation by a non-vanishing angle of rotation with respect to the direction of the line.

2. The optical arrangement according to claim 1 , wherein the non-vanishing angle of rotation is greater than 0 degrees and less than 90 degrees.

3. The optical arrangement according to claim 1 , the optical arrangement further comprising an adjustable holding device for the reshaping optical unit, wherein the adjustable holding device is configured in such a way that the angle of rotation is adjustable.

4. The optical arrangement according to claim 3 , wherein the adjustable holding device is configured such that the reshaping optical unit is rotateable about the aperture longitudinal direction.

5. The optical arrangement according to claim 3 , wherein the adjustable holding device is configured such that the reshaping optical unit rotateable about an axis perpendicular to the aperture longitudinal direction and to the direction of propagation.

6. The optical arrangement according to claim 1 , wherein the reshaping optical unit is configured such that, when the input laser beam having a high spatial coherence is radiated through the input aperture, the beam packet exiting the output aperture has a significantly reduced spatial coherence.

7. The optical arrangement according to claim 6 , wherein beam packet exiting the output aperture is incoherent.

8. The optical arrangement according to claim 1 , wherein the reshaping optical unit is configured such that adjacent beam segments of the input laser beam, upon passing through the reshaping optical unit, are rearranged into beam segments of the beam packet, wherein adjacent beam segments of the beam packet, upon passing through the reshaping optical unit, have covered different optical path lengths, such that the beam packet has a reduced spatial coherence.

9. The optical arrangement according to claim 8 , wherein the reshaping optical unit is formed from a monolithic, plate-like, 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 such that the beam segments of the input laser beam after incoupling through the input aperture are guided to the output aperture by reflection on the plate front side and the plate rear side.

10. The optical arrangement according to claim 8 , wherein the beam packet is incoherent.

11. The optical arrangement according to claim 1 , wherein the output aperture is rectangular and a long rectangle side extends parallel to the aperture longitudinal direction.

12. The optical arrangement according to claim 1 , wherein the output aperture extends trapezoidally or polygonally or band-like or freeform, and has a long preferred direction which extends parallel to the aperture longitudinal direction.

13. The optical arrangement according to claim 1 , wherein the homogenization optical unit is configured such that different beam segments of the beam packet are not intermixed or are not superimposed on one another with respect to an axis perpendicular to the direction of the line and perpendicular to the direction of propagation.

14. The optical arrangement according to claim 1 , wherein the homogenization optical unit comprises a transverse optical unit for focusing and/or optically imaging the beam packet with respect to an axis perpendicular to the direction of the line and perpendicular to the direction of propagation in the working plane or in a focal plane that is offset from the working plane.

15. The optical arrangement according to claim 1 , wherein the homogenization optical unit comprises an optical low-pass filter for filtering high spatial frequencies with respect to an axis perpendicular to the direction of the line and perpendicular to the direction of propagation.

16. A laser system for generating radiation having an intensity distribution, which has a line-shaped intensity profile in the beam cross section, the laser system comprising:
a laser light source for emitting laser radiation;
the optical arrangement according to claim 1 , wherein the optical arrangement is arranged such that the input laser beam for the input aperture is fed by the laser light source.

Assignees

• Trumpf Laser & Systemtechnik Gmbh

Inventors

• Beck Torsten
• Flamm Daniel
• Heimes Andreas
• Hellstern Julian
• Lingel Christian
• Marschall Felix
• Thierfelder Silke
• Tillkorn Christoph

Classifications

• B23K26/0738

  into a linear shape · CPC title

• B23K26/0608

  in the same heat affected zone [HAZ] (B23K26/0613, B23K26/0619 take precedence) · CPC title

• B23K26/0648

  comprising lenses · CPC title

• G02B27/145

  having sequential partially reflecting surfaces · CPC title

• G02B17/006 Primary

  Systems in which light light is reflected on a plurality of parallel surfaces, e.g. louvre mirrors, total internal reflection [TIR] lenses (Fresnel mirrors G02B5/09, Fresnel lenses G02B3/08) · CPC title