US 12,383,979 B2
Segmented beam-shaping element and laser processing installation
Daniel Flamm, Ludwigsburg (DE); and Keyou Chen, Tai Cang (CN)
Assigned to TRUMPF LASER—UND SYSTEMTECHNIK GMBH, Ditzingen (DE)
Filed by TRUMPF Laser—und Systemtechnik GmbH, Ditzingen (DE)
Filed on Apr. 19, 2022, as Appl. No. 17/723,498.
Application 17/723,498 is a continuation of application No. PCT/EP2020/079570, filed on Oct. 21, 2020.
Claims priority of application No. 10 2019 128 362.0 (DE), filed on Oct. 21, 2019.
Prior Publication US 2022/0234135 A1, Jul. 28, 2022
Int. Cl. B23K 26/064 (2014.01); G02B 27/42 (2006.01)
CPC B23K 26/064 (2015.10) [G02B 27/4233 (2013.01)] 18 Claims
OG exemplary drawing
 
1. A diffractive optical element for imposing a phase distribution on a transverse beam profile of a laser beam, the diffractive optical element comprising:
a sheet-like grating structure comprising a plurality of surface elements that adjoin one another, wherein each surface element has a phase shift value, and the phase shift values define a two-dimensional phase distribution, wherein
the two-dimensional phase distribution has a beam center position to be aligned with a center of a transverse beam profile of the laser beam, wherein the beam center position defines a radial direction in the sheet-like grating structure,
the surface elements of the sheet-like grating structure form a plurality of angle segments,
each of the plurality of angle segments has an azimuthal segment width with respect to the beam center position,
the phase shift values of the surface elements in the plurality of angle segments form radially symmetrical phase profiles with respect to the beam center position,
the radially symmetrical phase profiles form in a radial direction grating functions that have a same grating period, and
each of the grating functions has a respective segment grating phase.