Abstract: The invention relates to a device (1) for generating laser pulses, comprising a pump laser (1), which emits laser pulses at a pump wavelength (12) with a repetition frequency, wherein the pulse duration of the laser pulses is 0.5-100 ps, and an optical parametric oscillator (3) that converts the laser pulses of the pump laser (1) at least partially to laser pulses at a signal wavelength (10) and at an idler wavelength (11), which differs from the former, wherein the optical parametric oscillator (3) has an optical resonator (20), comprising a non-linear wavelength converter (22), which converts the laser pulses of the pump laser (1) to laser pulses at the signal wavelength (10) and at the idler wavelength (11), and an output coupling element (24), which couples at least some of the radiation out of the optical resonator (20).

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 waveguide with at least one core region (1) extending along the longitudinal extent of the optical waveguide, and with a first jacket (2) which, viewed in the cross section of the optical waveguide, surrounds the core region (1). The invention further relates to an optical arrangement with such an optical waveguide, and to a method for producing the optical waveguide. The object of the invention is to make available an optical waveguide for high-performance operation, which is improved in relation to the prior art in terms of mode instability. The invention achieves this object by virtue of the fact that the optical waveguide consists of crystalline material at least in the core region (1).

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 apparatus (1) for producing short synchronous radiation pulses at different wavelengths, particularly to an optically parametric oscillator, comprising at least one pump radiation source (2), preferably a pump laser, for outputting radiation at a pump wavelength, and a resonator (3) having a wavelength-dependent effective resonator length, wherein the resonator (3) has a non-linear wavelength converter (4) for producing radiation at a first and a second wavelength; a dispersive element (5) having a strong wavelength-dependent delay characteristic; and a coupling-out element (6) for at least partially coupling-out the radiation from the resonator (3). In addition, the invention relates to a method for producing short radiation pulses by means of an apparatus (1), particularly an optically parametric oscillator.

Abstract: The invention relates to an optical waveguide with at least one core region (1) extending along the longitudinal extent of the optical waveguide, and with a first jacket (2) which, viewed in the cross section of the optical waveguide, surrounds the core region (1). The invention further relates to an optical arrangement with such an optical waveguide, and to a method for producing the optical waveguide. The object of the invention is to make available an optical waveguide for high-performance operation, which is improved in relation to the prior art in terms of mode instability. The invention achieves this object by virtue of the fact that the optical waveguide consists of crystalline material at least in the core region (1).

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 apparatus (1) for producing short synchronous radiation pulses at different wavelengths, particularly to an optically parametric oscillator, comprising at least one pump radiation source (2), preferably a pump laser, for outputting radiation at a pump wavelength, and a resonator (3) having a wavelength-dependent effective resonator length, wherein the resonator (3) has a non-linear wavelength converter (4) for producing radiation at a first and a second wavelength; a dispersive element (5) having a strong wavelength-dependent delay characteristic; and a coupling-out element (6) for at least partially coupling-out the radiation from the resonator (3). In addition, the invention relates to a method for producing short radiation pulses by means of an apparatus (1), particularly an optically parametric oscillator.

Abstract: An apparatus for laser processing of a material, in particular the eye cornea, emits on to the material a train (18?) of laser radiation pulses having a pulse duration in the femtosecond range. The pulse train comprises a multiplicity of successive pulse groups, each pulse group comprising at least two laser radiation pulses (20?, 22?). The pulses of a pulse group are directed at substantially the same processing site of the material, but the pulses of successive groups are directed at substantially different processing sites of the material. According to the invention the time interval between successive laser radiation pulses of a pulse group is in the nanosecond range. In particular, the intensity or energy of the pulses within a pulse group is graduated, in such a way that a preceding prepulse (20?) has substantially lower intensity or energy than a following main pulse (22?).

Abstract: A fiber laser for the production of self-similar pulses contains a pumped source and a linear resonator. The linear resonator has two reflectors. The laser further includes a polarization-maintaining fiber doped with an amplifying medium with a normal dispersion ?2>0 in the frequency range prescribed by the amplifying medium and a dispersion-compensating element with an anomalous dispersion ?2<0. The laser further includes an element for decoupling radiation and a non-linear mode coupling element with a modulation depth >0. The fiber, dispersion-compensating element, element for decoupling radiation and non-linear mode coupling element are disposed between the two reflectors in a common beam path delimited by the resonators. The total dispersion of the components disposed in the beam path of the resonator is normal.

Abstract: Apparatus and method for laser treatment of a biological material An apparatus for laser processing of a material, in particular the eye cornea, emits on to the material a train (18?) of laser radiation pulses having a pulse duration in the femtosecond range. The pulse train comprises a multiplicity of successive pulse groups, each pulse group comprising at least two laser radiation pulses (20?, 22?). The pulses of a pulse group are directed at substantially the same processing site of the material, but the pulses of successive groups are directed at substantially different processing sites of the material. According to the invention the time interval between successive laser radiation pulses of a pulse group is in the nanosecond range. In particular, the intensity or energy of the pulses within a pulse group is graduated, in such a way that a preceding prepulse (20?) has substantially lower intensity or energy than a following main pulse (22?).

Abstract: A monolithic, non-planar ring laser having Q-switched single-frequency operation comprises a diode laser as the pumping light source of which the pumping light is coupled to a ring laser crystal (2) that comprises at least three total reflection faces B, C and D and a dielectrically coated crystal face A designed as a coupling and decoupling mirror. To obtain high-power laser pulses in the highly stable single-frequency mode and further to achieve compactness, the following design solutions are offered: 1. A switching crystal (20) having an appropriate index of refraction which can be moved to a distance of about one laser beam wavelength to one of the total reflection faces B, C, D of the ring laser crystal (2) to decouple the evanescent wave field and thereby to suppress laser oscillation, said switching crystal being displaceable away from the total reflection face to generate laser pulses, 2.