Device, laser system and method for combining coherent laser beams

An apparatus for combining a plurality of coherent laser beams, comprising:

• a splitting device for splitting an input laser beam into the plurality of coherent laser beams,
• a plurality of phase setting devices each for adjusting a respective phase of one of the coherent laser beams, and
• a beam combining device for combining the coherent laser beams, which emanate from a plurality of grid positions of a grid arrangement, to form at least one combined laser beam,
• wherein the beam combining device has a microlens arrangement with exactly one microlens array for forming the at least one combined laser beam,
• wherein the plurality of grid positions are arranged in a first direction at a distance of a focal length fML of the microlens array upstream of the microlens array and having a distance δx from one another, which is given by
• δx=Px
• where px denotes a pitch of microlenses of the microlens array in the first direction;
• and
• wherein the coherent laser beams have at the grid positions a beam diameter 2ωFMLx, which is given by:
• 2ωfMLx=λLfML/Px,
• where λL denotes a laser wavelength of the input laser beam.

An apparatus for combining a plurality of coherent laser beams, comprising:

• a splitting device for splitting an input laser beam into the plurality of coherent laser beams,
• a plurality of phase setting devices each for adjusting a respective phase of one of the coherent laser beams,
• a beam combining device for combining the coherent laser beams, which emanate from a plurality of grid positions of a grid arrangement, to form at least one combined laser beam,
• a seed laser source configured to produce a seed laser beam, and direct the seed laser bean as the input laser beam of the splitting device, and
• a further apparatus for combining a plurality of further coherent laser beams, comprising:
• a further splitting device for splitting the seed laser beam into the plurality of further coherent laser beams,
• a plurality of further phase setting devices for adjusting a respective phase of one of the further coherent laser beams, and
• a further beam combining device for combining the further coherent laser beams emanating from a plurality of further grid positions of a further grid arrangement, with the further beam combining device comprising a further microlens arrangement having at least one further microlens array, and a further control device which is configured to adjust the respective phase of one of the further coherent laser beams on the basis of an arrangement of the respective further grid position within the further grid arrangement in order to combine the coherent further laser beams to form a laser beam that is diffracted into exactly one order of diffraction, the diffracted laser beam forming the input laser beam of the splitting device of the apparatus,
• wherein the beam combining device has a microlens arrangement with exactly one microlens array for forming the at least one combined laser beam.