Abstract: An apparatus for combining a plurality of coherent laser beams includes at least N?1 phase setting devices configured to set a respective phase (??n) 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 includes a microlens arrangement having at least two microlens arrays configured to form the at least one combined laser beam.

Abstract: Methods, devices, and systems for welding optical fibers and perforated elements by pulsed laser beam are provided. In one aspect, a method includes focusing a pulsed laser beam onto a region of a joining surface formed by an outer circumference of an optical fiber and an inner circumference of a hole of a perforated element, a beam direction of the pulsed laser beam running in an axial direction of the joining surface, and moving a laser focus of the pulsed laser beam in the region axially in or counter to the beam direction to produce at least one weld seam in the region. The optical fiber and the perforated element are locally melted in the region by the pulsed laser beam focused into a material of the optical fiber and a material of the perforated element and are thereby welded to one another.

Abstract: An apparatus for combining a plurality of coherent laser beams includes a splitting device for splitting an input laser beam into the plurality of coherent laser beams, a plurality of phase setting devices 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. The beam combining device has a microlens arrangement with exactly one microlens array for forming the at least one combined laser beam.

Abstract: An apparatus for combining a plurality of coherent laser beams includes a splitting device configured to split an input laser beam into the plurality of coherent laser beams, a plurality of phase setting devices configured to adjust a respective phase of one of the plurality of coherent laser beams, and a beam combining device configured to combine the plurality of coherent laser beams, which emanate from a plurality of grid positions of a grid arrangement. The beam combining device includes a microlens arrangement having at least two microlens arrays. The apparatus further includes a controller configured to adjust a respective phase of a respective one of the plurality of coherent laser beams and/or vary a respective phase of a respective one of the plurality of coherent laser beams.

Abstract: An optical assembly includes a beam path, passing, in succession, through multiple microlens arrays and a Fourier lens assembly. The microlens arrays have a uniform aperture of their microlenses, and the entirety of the microlens arrays has an effective focal length. The optical assembly further includes an adjustment mechanism, configured to adjust a mutual optical distance of at least some of the microlens arrays in the beam path, thereby setting the effective focal length of the entirety of the microlens arrays. The adjustment mechanism has multiple adjustment positions i=1, . . . , M wherein M is a natural number ?2, i is an adjustment position index, at which the term a 2 ? · f ML , i in each case essentially smoothly results in a natural number Ni. ? is a center wavelength, fML,i is an effective focal length fML of the entirety of the microlens arrays set by the adjustment position i.

Abstract: Methods, devices, and systems for welding optical fibers and perforated elements by pulsed laser beam are provided. In one aspect, a method includes focusing a pulsed laser beam onto a region of a joining surface formed by an outer circumference of an optical fiber and an inner circumference of a hole of a perforated element, a beam direction of the pulsed laser beam running in an axial direction of the joining surface, and moving a laser focus of the pulsed laser beam in the region axially in or counter to the beam direction to produce at least one weld seam in the region. The optical fiber and the perforated element are locally melted in the region by the pulsed laser beam focused into a material of the optical fiber and a material of the perforated element and are thereby welded to one another.

Abstract: An optical assembly includes a beam path, passing, in succession, through multiple microlens arrays and a Fourier lens assembly. The microlens arrays have a uniform aperture of their microlenses, and the entirety of the microlens arrays has an effective focal length. The optical assembly further includes an adjustment mechanism, configured to adjust a mutual optical distance of at least some of the microlens arrays in the beam path, thereby setting the effective focal length of the entirety of the microlens arrays. The adjustment mechanism has multiple adjustment positions i=1, . . . , M wherein M is a natural number ?2, i is an adjustment position index, at which the term a 2 ? · f ML , i in each case essentially smoothly results in a natural number Ni. ? is a center wavelength, fML,i is an effective focal length fML of the entirety of the microlens arrays set by the adjustment position i.

Abstract: An apparatus for combining a plurality of coherent laser beams includes at least N?1 phase setting devices configured to set a respective phase (??n) 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 includes a microlens arrangement having at least two microlens arrays configured to form the at least one combined laser beam.