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: The invention relates to an optical array comprising a splitting element (1) which splits an input beam (E) into at least two partial beams (T1, T2, T3, T4), at least one optical element (V1, V2, V3, V4, MV) through which at least one of the partial beams (T1, T2, T3, T4) propagates, and at least one combining element (4) which spatially superimposes the partial beams (T1, T2, T3, T4) in one output beam (A). The object of the invention is to provide an optical array which is improved over the prior art and which permits effective and simple splitting of the input light beam, in particular a laser beam with pulsed or continuous emission. The invention achieves this object in that the splitting element (1) and/or the combining element (4) each have a partially reflective element (2, 2?) which reflects the radiation of the input beam (E) or of the output beam (A) two or more times, wherein the partially reflective element (2, 2?) has zones (a, b, c, d) of different reflectivity.

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: The invention relates to an optical array comprising a splitting element (1) which splits an input beam (E) into at least two partial beams (T1, T2, T3, T4), at least one optical element (V1, V2, V3, V4, MV) through which at least one of the partial beams (T1, T2, T3, T4) propagates, and at least one combining element (4) which spatially superimposes the partial beams (T1, T2, T3, T4) in one output beam (A). The object of the invention is to provide an optical array which is improved over the prior art and which permits effective and simple splitting of the input light beam, in particular a laser beam with pulsed or continuous emission. The invention achieves this object in that the splitting element (1) and/or the combining element (4) each have a partially reflective element (2, 2?) which reflects the radiation of the input beam (E) or of the output beam (A) two or more times, wherein the partially reflective element (2, 2?) has zones (a, b, c, d) of different reflectivity.

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.