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: An optical arrangement for pulse compression of a pulsed laser beam includes a grating arrangement comprising at least one diffraction grating, and a beam-expanding device comprising at least one beam-expanding optical element for forming a divergent pulsed laser beam that enters the grating arrangement divergently.

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: A method of propagating a laser signal through an optical waveguide and a waveguide laser system provide a novel way of stabilizing the beam emitted by a fiber laser system above the mode instability threshold wherein the beat length of two or more interfering transverse modes of the laser signal in the optical waveguide is modulated in time.

Abstract: The invention relates to an optical waveguide (3) as a laser medium or as a gain medium for high-power operation, wherein the optical waveguide (3) is an optical fiber, the light-guiding core of which, at least in sections, is doped with rare earth ions. It is an object of the invention to provide an optical waveguide as a laser or a gain medium, and a laser/amplifier combination realized therewith, in which the output signal of the laser or gain medium is better stabilized. The invention achieves this object by virtue of the maximum small signal gain of the optical waveguide (1) being up to 60 dB, preferably up to 50 dB, more preferably up to 40 dB, even more preferably up to 30 dB, on account of the concentration of the rare earth ions and/or the distribution thereof in the light-guiding core. Moreover, the invention relates to the use of such an optical waveguide as an amplifier fiber (3) in a laser/amplifier combination.

Abstract: A method of propagating a laser signal through an optical waveguide and a waveguide laser system provide a novel way of stabilizing the beam emitted by a fiber laser system above the mode instability threshold wherein the beat length of two or more interfering transverse modes of the laser signal in the optical waveguide is modulated in time.

Abstract: The invention relates to a method and corresponding devices for reducing mode instability in an optical waveguide (1), a light signal becoming unstable in the optical waveguide (1) beyond an output power threshold and energy being transformed from a basic mode into higher order modes. The invention proposes a reduction in temperature variation (2) along the optical waveguide (1) and/or a reduction in changes in the optical waveguide (1) that are caused by spatial temperature variation as a result of mode interference.

Abstract: The invention relates to a method and corresponding devices for reducing mode instability in an optical waveguide (1), a light signal becoming unstable in the optical waveguide (1) beyond an output power threshold and energy being transformed from a basic mode into higher order modes. The invention proposes a reduction in temperature variation (2) along the optical waveguide (1) and/or a reduction in changes in the optical waveguide (1) that are caused by spatial temperature variation as a result of mode interference.