US 11,796,720 B2
Apparatus, laser system and method for combining coherent laser beams
Christoph Tillkorn, Villingendorf (DE); Daniel Flamm, Kornwestheim (DE); Florian Jansen, Villingen-Schwenningen (DE); Torsten Beck, Stuttgart (DE); Hans-Juergen Otto, Schramberg (DE); Julian Hellstern, Rottweil (DE); Andreas Heimes, Renningen (DE); and Maike Prossotowicz, Aichhalden (DE)
Assigned to TRUMPF LASER GMBH, Schramberg (DE)
Filed by TRUMPF Laser GmbH, Schramberg (DE)
Filed on Jan. 15, 2021, as Appl. No. 17/149,763.
Application 17/149,763 is a continuation of application No. PCT/EP2019/069324, filed on Jul. 18, 2019.
Claims priority of application No. 10 2018 211 971.6 (DE), filed on Jul. 18, 2018.
Prior Publication US 2021/0165135 A1, Jun. 3, 2021
Int. Cl. G02B 3/00 (2006.01); G02B 27/12 (2006.01); G02B 27/30 (2006.01); G02B 3/04 (2006.01)
CPC G02B 3/0037 (2013.01) [G02B 3/04 (2013.01); G02B 27/123 (2013.01); G02B 27/30 (2013.01)] 28 Claims
OG exemplary drawing
 
1. An apparatus for combining a plurality of coherent laser beams, the apparatus comprising:
at least N−1 phase setting devices configured to set a respective phase (δφn) of a respective one of the plurality of coherent laser beams; and
a beam combination device configured to combine the plurality of coherent laser beams to form at least one combined laser beam, the beam combination device including a microlens arrangement having at least two microlens arrays configured to form the at least one combined laser beam;
wherein the respective phase (δφn) of the respective one of the plurality of coherent laser beams is given by:
δφn=−(2π/λL)fE(mnλL/p)2,
wherein N denotes a number of the plurality of coherent laser beams, n denotes an index for an n-th coherent laser beam, p denotes a grid spacing of microlenses of a respective microlens array, fE denotes an effective focal length of the microlens arrangement, and λL denotes a laser wavelength, and wherein the following applies:

OG Complex Work Unit Math