Abstract: A pulse modification apparatus includes at least one pulse stretcher for dispersive stretching of laser pulses and/or at least one pulse compressor for dispersive compression of the laser pulses, an actuator for setting a dispersion of the at least one pulse stretcher or a dispersion of the at least one pulse compressor by setting at least one manipulated variable, a controller for controlling the actuator based on a measurement signal, and an ambient sensor for detecting at least one ambient parameter as the measurement signal. The dispersion of the at least one pulse stretcher or the dispersion of the at least one pulse compressor is dependent on the at least one ambient parameter.

Abstract: A passive mode-coupled fiber oscillator includes a bidirectional loop, a unidirectional loop, and a 3x3 coupler. The bidirectional loop and the unidirectional loop are coupled to one another via the 3x3 coupler. The bidirectional loop includes a first amplification fiber that is doped using at least one element selected from the group consisting of ytterbium, neodymium, erbium, thulium, and holmium. The fiber oscillator further includes a dispersion compensation element. The fiber oscillator has an anomalous dispersion overall.

Abstract: A passively mode-coupled fiber oscillator includes a bidirectional loop, a unidirectional loop, and a 3×3 coupler. The bidirectional loop and the unidirectional loop are coupled to each other by the 3×3 coupler. The bidirectional loop includes a first amplifying fiber. The fiber oscillator has overall a normal dispersion.

Abstract: A laser system includes a laser radiation source for emitting light, and an optical fiber unit that includes an optical fiber. The optical fiber includes a light guiding region, an input coupling end having a first fiber end surface for coupling the light into the light guiding region, and an output coupling end having a second fiber end surface for coupling the light out of the light guiding region. The laser system further includes a coupling device for coupling the light into the optical fiber unit, a reflection element configured to reflect the light coupled out of the light guiding region back toward the second fiber end surface to be coupled back into the light guiding region via the second fiber end surface, and a measuring device configured to capture the light reflected by the reflection element.

Abstract: An optical fiber unit includes an optical fiber. The optical fiber includes a light guiding region configured for guiding light through the optical fiber, an input coupling end having a first fiber end surface for coupling the light into the light guiding region, and an output coupling end having a second fiber end surface for coupling the light out of the light guiding region. The optical fiber unit further includes a first end piece arranged at one of the input coupling end and the output coupling end. The first end piece is configured to couple the light into the light guiding region or couple the light out of the light guiding region. The first end piece includes a reflection element configured to divert a portion of the light propagating along a direction of propagation through the light guiding region away from the direction of propagation.

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: A laser system for nonlinear pulse compression includes a laser source configured to generate laser pulses with a pulse energy of at least 50 mJ, a spectral broadening device for spectrally broadening the high-energy laser pulses using self-phase modulation, and a compression device including a grating compressor having at least two diffraction gratings and configured to compress the spectrally broadened high-energy laser pulses. The laser system is configured to generate a pulse duration of the high-energy laser pulses of less than 100 fs.

Abstract: A method for amplifying an ultrashort laser pulse includes: a) stretching the ultrashort laser pulse in time, b) amplifying the time-stretched laser pulse, c) compressing the amplified time-stretched laser pulse, with at least one gain phase contribution selected from a group consisting of a gain dynamics phase contribution of the laser pulse that emerges as a change in a nonlinear phase on account of gain dynamics in step b), a gain bandwidth phase contribution of the laser pulse that emerges as a change in the nonlinear phase on account of a gain bandwidth in step b), and a combination thereof, being compensated by virtue of d) an additional phase contribution being imparted on the laser pulse prior to step c) and/or e) a spectrum of the laser pulse being changed, in such a way that the at least one gain phase contribution is compensated after step c).

Abstract: In methods and devices for generating a laser pulse of an excitation laser that is actuated by a driver in response to a triggering time of a trigger signal, the driver actuation signal is generated taking into account the time interval between the triggering time and a preceding triggering time.

Abstract: A device for transporting pulsed laser radiation includes a pulse duration setting device configured for setting a transport pulse duration of the pulsed laser radiation. the device further includes a hollow core optical fiber having a hollow core surrounded by a material. The hollow core optical fiber is configured to be operated with beam path parameter values that are present at the first fiber end and lie in a target tolerance range. The device further includes a fiber input coupling device configured to couple the pulsed laser radiation into the hollow core optical fiber with the beam path parameter values that lie in the target tolerance range. the transport pulse duration is set so that input coupling of the pulsed laser radiation into the hollow core is provided for all of the beam path parameter values in the target tolerance range.

Abstract: A pulse compressor includes a plurality of optical components. The plurality of optical components includes a diffraction grating. A first optical component of the optical components is fastened to base plate by at least first and second intermediate elements that are laser-welded to one another. The first intermediate element is fastened to the base plate and the second intermediate element is fastened to the optical component. A joining surface of the first and second intermediate elements is formed as a bearing recess and another joining surface is curved. At least the laser-welded joining surfaces of the first optical component, the base plate, and the first and second intermediate elements are formed from materials for which a difference in their coefficients of thermal expansion is less than 10e-6/K.

Abstract: The invention relates to dispersion adjustment units for electromagnetic radiation having a spectral width, e.g., for laser pulses. The dispersion adjustment unit includes at least one dispersive element for producing angular dispersion in an angular dispersion region limited by two interaction regions of the electromagnetic radiation with the at least one dispersive element. In the angular dispersion region, individual spectral components of the electromagnetic radiation are associated with optical paths extending at an angle to one another. Furthermore, the dispersion adjustment unit includes an optical unit that is arranged in the angular dispersion region and includes an optical element that transmits the electromagnetic radiation. The optical element effects an incidence-angle-dependent parallel offset of the individual spectral components of the electromagnetic radiation with respect to the propagation of the individual spectral components before and after the optical unit.

Abstract: Laser systems are described that each include at least one excitation laser, a high frequency laser pulse source, and a beam switchover device. The beam switchover device is configured to be switched, in order a) in a high-frequency functional position to guide at least one GHz laser pulse train with a pulse repetition rate of individual pulses in the GHz laser pulse train of at least 0.5 GHz from the high frequency laser pulse source to a target position, and b) in a low-frequency functional position to guide at least one low-frequency laser pulse train with a pulse repetition rate of individual pulses in the low-frequency laser pulse train of less than 0.5 GHz from the at least one excitation laser to the target position.

Abstract: A fiber amplification system is provided for amplifying a laser pulse signal, e.g., an oscillator signal of an oscillator device. The fiber amplification system includes a fiber pre-amplification system having a short, fundamental-mode and step-index fiber configured to pre-amplify the laser pule signal to generate a seed signal and a main amplification system having a large core fiber configured to amplify the seed signal. The short, fundamental-mode step-index fiber can have a length no longer than about 30 cm, and a mode field diameter no less than about 30 ?m, e.g., in a range from 30 ?m to 60 ?m, as well as a high doping concentration needed to provide an absorption length no more than about 30 cm, for providing the seed signal for the large core fiber with low non-linearity.

Abstract: A laser amplifier system includes: a fiber-laser pre-amplifier system for pre-amplifying initial laser pulses and outputting pre-amplified laser pulses; an intermediate-compressor for temporally partially compressing the pre-amplified laser pulses; a solid-state post-amplifier for post-amplifying temporally partially compressed pre-amplified laser pulses and for outputting post-amplified laser pulses; and a post-compressor for temporally compressing the post-amplified laser pulses to generate the output laser pulses.

Abstract: In methods and devices for generating a laser pulse of an excitation laser that is actuated by a driver in response to a triggering time of a trigger signal, the driver actuation signal is generated taking into account the time interval between the triggering time and a preceding triggering time.

Abstract: Fiber mounting units for supporting an optical fiber for fiber laser systems are disclosed and include a base body having a fiber end attachment section, a fiber guide section, and a connection section arranged between the fiber end attachment section and the fiber guide section. The fiber end attachment section is adapted to attach a receiving element, which holds a fiber end portion of the optical fiber, the fiber guide section is adapted to guide a fiber central portion of the optical fiber, and the connection section is configured as a flexure bearing between the fiber end attachment section and the fiber guide section.

Abstract: The invention relates to dispersion adjustment units for electromagnetic radiation having a spectral width, e.g., for laser pulses. The dispersion adjustment unit includes at least one dispersive element for producing angular dispersion in an angular dispersion region limited by two interaction regions of the electromagnetic radiation with the at least one dispersive element. In the angular dispersion region, individual spectral components of the electromagnetic radiation are associated with optical paths extending at an angle to one another. Furthermore, the dispersion adjustment unit includes an optical unit that is arranged in the angular dispersion region and includes an optical element that transmits the electromagnetic radiation. The optical element effects an incidence-angle-dependent parallel offset of the individual spectral components of the electromagnetic radiation with respect to the propagation of the individual spectral components before and after the optical unit.

Abstract: A fiber amplification system is provided for amplifying a laser pulse signal, e.g., an oscillator signal of an oscillator device. The fiber amplification system includes a fiber pre-amplification system having a short, fundamental-mode and step-index fiber configured to pre-amplify the laser pule signal to generate a seed signal and a main amplification system having a large core fiber configured to amplify the seed signal. The short, fundamental-mode step-index fiber can have a length no longer than about 30 cm, and a mode field diameter no less than about 30 ?m, e.g., in a range from 30 ?m to 60 ?m, as well as a high doping concentration needed to provide an absorption length no more than about 30 cm, for providing the seed signal for the large core fiber with low non-linearity.

Abstract: Fiber mounting units for supporting an optical fiber for fiber laser systems are disclosed and include a base body having a fiber end attachment section, a fiber guide section, and a connection section arranged between the fiber end attachment section and the fiber guide section.