Abstract: It is an object of the invention to provide a method and a corresponding laser system that are simple and robust and that are able to provide sub-100 fs laser pulses using nonlinear frequency-conversion. The method of the invention comprises the steps of generating pulsed laser radiation at a fundamental wavelength, increasing the spectral bandwidth of the laser radiation by passing the laser radiation through a periodically poled nonlinear crystal material whose poling period is larger than or smaller than the poling period satisfying the quasi-phase-matching condition at the fundamental wavelength, and frequency-converting the spectrally broadened laser radiation.

Abstract: The invention relates to a laser device comprising a laser source (1), which is configured to emit pulsed laser radiation (2) with a spectrum in the form of a frequency comb having a plurality of equidistant spectral lines, an optical modulator (3), which is configured to shift the frequency of the laser radiation (2), and a control unit (10), which is configured to control the modulator (3) by means of a control signal (6). It is the object of the present invention to demonstrate an improved way, compared to the prior art, of generating an optical frequency comb that is stabilized in terms of the CEO frequency, in which the CE phase is also adjustable. To this end, the invention proposes that the laser radiation (2) emitted by the laser source (1) is stabilized in terms of the carrier-envelope frequency. Furthermore, the invention relates to a method of generating an optical frequency comb.

Abstract: The invention relates to a device for generating temporally spaced light pulses. Said device comprises a first light source which emits a first train of light pulses, a second light source which emits a second train of light pulses, and a phase-locked loop which regulates the relative phase of the light-pulse trains towards a target value. When the two light-pulse trains each pass through an optical transmission path to an application site that is spatially remote from the light sources, fluctuating phase differences in the light-pulse trains at the application site occur due to external influences along the transmission paths. The object of the invention is to provide an improved device for generating temporally spaced light pulses. In particular, the above-mentioned fluctuating phase differences are intended to be prevented.

Abstract: The invention relates to an illumination device, in particular for a confocal microscope. The object of the invention is to provide an illumination device which operates with a plurality of current-modulated semiconductor-based light sources, in which the light emission is as free as possible from distortions due to dynamic delays of the light emission in the output beam.

Abstract: The disclosure relates to a device for generating pulsed laser radiation, having a laser resonator which contains a laser-active medium (EDF1, EDF2), a pump light source which optically pumps the laser-active medium (EDF1, EDF2) at a pump power (P), and a mode coupling device which is intended to effect phase coupling of the modes of the laser radiation circulating in the laser resonator, so that the spectrum of the laser radiation forms a frequency comb. The disclosure also relates to a method for designing or operating such a device. The disclosure proposes that phase noise of the frequency comb, i.e. the width of spectral lines of the frequency comb, is minimized at a predetermined useful frequency by adjusting the frequency of the pump power fixed point (vfix,pump) of the frequency comb.

Abstract: The invention relates to a method for modulating the resonant frequency of an optical resonator (1) in accordance with a periodic, not necessarily harmonic, modulation signal (Umod(t)). Fast modulation of an optical resonator is intended to be made possible in which the current resonant frequency follows the modulation signal (Umod(t)) as precisely as possible, and specifically at a fundamental frequency of the modulation signal in the kHz range. To do this, the invention proposes the following method steps: deriving an error signal (E(t)) from a light field circulating in the resonator (1), wherein the error signal (E(t)) indicates the deviation of the optical frequency of the light field from a target value, deriving a first actuating signal (S1(t)) from the error signal (E(t)) by means of a controller (6), generating a second actuating signal (S2(t)), which has actuating-signal components at one or more harmonics (fmod, 2fmod, . . .

Abstract: The disclosure relates to a retaining arrangement with a carrier platform (2), for example in laser systems, to which at least one optical element (3) is fixed. The disclosure specifies a retaining arrangement for optical elements which ensures improved beam position stability with as little effort as possible. For this purpose, the carrier platform (2) is connected to a base (8) at bearing points (5) via a respective elastically compliant and/or damping connecting structure (6). The connecting structure (6) is designed to elastically absorb thermal expansions of the carrier platform (2). The at least one optical element (3) is located at a neutral point (13) and/or on a neutral axis on the carrier platform (2), wherein this neutral point (13) or the neutral axis is positionally stable relative to the base (8) during thermal deformation of the carrier platform (2).

Abstract: The invention relates to a method for homogenization of the output beam profile of a multimode optical waveguide (10). The method comprises the following method steps: splitting input radiation (2) of coherent light over two or more beam paths (I-IV), modulating the radiation in at least one of the beam paths (I-IV), combining the beam paths (I-IV) by superimposing the modulated radiation onto the input (9) of the multimode waveguide (10), where the radiation forms a temporally variable interference pattern, and propagating the radiation using the multimode waveguide (10). The invention furthermore relates to a device for carrying out the method.

Abstract: The invention relates to a laser device comprising a laser source (1), which is configured to emit pulsed laser radiation (2) with a spectrum in the form of a frequency comb having a plurality of equidistant spectral lines, an optical modulator (3), which is configured to shift the frequency of the laser radiation (2), and a control unit (10), which is configured to control the modulator (3) by means of a control signal (6). It is the object of the present invention to demonstrate an improved way, compared to the prior art, of generating an optical frequency comb that is stabilized in terms of the CEO frequency, in which the CE phase is also adjustable. To this end, the invention proposes that the laser radiation (2) emitted by the laser source (1) is stabilized in terms of the carrier-envelope frequency. Furthermore, the invention relates to a method of generating an optical frequency comb.

Abstract: The invention relates to an illumination device, in particular for a confocal microscope. The object of the invention is to provide an illumination device which operates with a plurality of current-modulated semiconductor-based light sources, in which the light emission is as free as possible from distortions due to dynamic delays of the light emission in the output beam.

Abstract: Disclosed herein is an all-fiber, easy to use, wavelength tunable, ultrafast laser based on soliton self-frequency-shifting in an Er-doped polarization-maintaining very large mode area (PM VLMA) fiber. The ultrafast laser system may include an all polarization-maintaining (PM) fiber mode-locked seed laser with a pre-amplifier; a Raman laser including a cascaded Raman resonator and an ytterbium (Yb) fiber laser cavity; an amplifier core-pumped by the Raman laser, the amplifier including an erbium (Er) doped polarization maintaining very large mode area (PM Er VLMA) optical fiber and a passive PM VLMA fiber following the PM Er VLMA, the passive PM VLMA for supporting a spectral shift to a longer wavelength.

Abstract: The invention relates to a method for homogenization of the output beam profile of a multimode optical waveguide (10). The method comprises the following method steps: splitting input radiation (2) of coherent light over two or more beam paths (I-IV), modulating the radiation in at least one of the beam paths (I-IV), combining the beam paths (I-IV) by superimposing the modulated radiation onto the input (9) of the multimode waveguide (10), where the radiation forms a temporally variable interference pattern, and propagating the radiation using the multimode waveguide (10). The invention furthermore relates to a device for carrying out the method.

Abstract: The invention relates to a method for modulating the resonant frequency of an optical resonator (1) in accordance with a periodic, not necessarily harmonic, modulation signal (Umod(t)). Fast modulation of an optical resonator is intended to be made possible in which the current resonant frequency follows the modulation signal (Umod(t)) as precisely as possible, and specifically at a fundamental frequency of the modulation signal in the kHz range. To do this, the invention proposes the following method steps: deriving an error signal (E(t)) from a light field circulating in the resonator (1), wherein the error signal (E(t)) indicates the deviation of the optical frequency of the light field from a target value, deriving a first actuating signal (S1(t)) from the error signal (E(t)) by means of a controller (6), generating a second actuating signal (S2(t)), which has actuating-signal components at one or more harmonics (fmod, 2fmod, . . .

Abstract: The invention relates to a device for generating temporally spaced light pulses. Said device comprises a first light source which emits a first train of light pulses, a second light source which emits a second train of light pulses, and a phase-locked loop which regulates the relative phase of the light-pulse trains towards a target value. When the two light-pulse trains each pass through an optical transmission path to an application site that is spatially remote from the light sources, fluctuating phase differences in the light-pulse trains at the application site occur due to external influences along the transmission paths. The object of the invention is to provide an improved device for generating temporally spaced light pulses. In particular, the above-mentioned fluctuating phase differences are intended to be prevented.

Abstract: A method for generating pulsed laser radiation in the spectral range from 860 nm to 1000 nm is disclosed, including the steps of generating pulsed laser radiation in the spectral range from 1500 nm to 1600 nm, preferably at a wavelength of 1560 nm; shifting the wavelength of the pulsed laser radiation to a longer wavelength of at least 1720 nm, and preferably to 1840 nm; amplifying the wavelength-shifted pulsed laser radiation in a Thulium-doped gain medium so that the Thulium-doped gain medium is pumped in an in-band pumping scheme; and frequency-doubling the amplified wavelength-shifted pulsed laser radiation. A laser system suitable for practicing the method is also disclosed.

Abstract: The invention relates to a laser device comprising a laser source (1), which is configured to emit pulsed laser radiation (2) with a spectrum in the form of a frequency comb having a plurality of equidistant spectral lines, an optical modulator (3), which is configured to shift the frequency of the laser radiation (2), and a control unit (10), which is configured to control the modulator (3) by means of a control signal (6). It is the object of the present invention to demonstrate an improved way, compared to the prior art, of generating an optical frequency comb that is stabilized in terms of the CEO frequency, in which the CE phase is also adjustable. To this end, the invention proposes that the laser radiation (2) emitted by the laser source (1) is stabilized in terms of the carrier-envelope frequency. Furthermore, the invention relates to a method of generating an optical frequency comb.

Abstract: It is an object of the invention to provide a method and a corresponding laser system that are simple and robust and that are able to provide sub-100 fs laser pulses using nonlinear frequency-conversion. The method of the invention comprises the steps of generating pulsed laser radiation at a fundamental wavelength, increasing the spectral bandwidth of the laser radiation by passing the laser radiation through a periodically poled nonlinear crystal material whose poling period is larger than or smaller than the poling period satisfying the quasi-phase-matching condition at the fundamental wavelength, and frequency-converting the spectrally broadened laser radiation.

Abstract: A method for generating stabilized, pulsed laser radiation is disclosed, the method including at least the steps of generating pulsed laser radiation at a repetition frequency, wherein the spectrum of the pulsed laser radiation is a frequency comb having a number of equidistant spectral lines; deriving a first controlled variable from the pulsed laser radiation by means of phase comparison with a high-frequency reference signal; generating narrow-band continuous-wave laser radiation at a reference wavelength; setting the reference wavelength in accordance with a first manipulated variable derived from the first controlled variable; deriving a second controlled variable by means of superposition of the pulsed laser radiation and the continuous-wave laser radiation; and setting the repetition frequency in accordance with a second manipulated variable derived from the second controlled variable. A device for generating stabilized, pulsed laser radiation compatible with the method is also disclosed.

Abstract: The invention relates to a method of generating frequency-tripled laser radiation (THG). It is the object of the invention to demonstrate an efficient approach to generating frequency-tripled laser radiation.

Abstract: A method for generating pulsed laser radiation in the spectral range from 860 nm to 1000 nm is disclosed, including the steps of generating pulsed laser radiation in the spectral range from 1500 nm to 1600 nm, preferably at a wavelength of 1560 nm; shifting the wavelength of the pulsed laser radiation to a longer wavelength of at least 1720 nm, and preferably to 1840 nm; amplifying the wavelength-shifted pulsed laser radiation in a Thulium-doped gain medium so that the Thulium-doped gain medium is pumped in an in-band pumping scheme; and frequency-doubling the amplified wavelength-shifted pulsed laser radiation. A laser system suitable for practicing the method is also disclosed.