Abstract: The aim of the present disclosure is to enable a fast CE phase evaluation of the laser pulses, in particular in real time, including for multi-cycle pulses. Said aim is achieved by providing a polarization gating stage (8) for changing the laser pulses (7) to be evaluated in the phase and subsequent phase evaluation stage (15) for measuring the phase position of the changed laser pulses. The descriptions in the present disclosure can be used for example in laser technology for producing and monitoring single-cycle pulses.

Abstract: The present disclosure relates to a method and to a device (1) by which a train (2, 2) of short laser pulses of a mode-coupled laser (3) is compensated with respect to the carrier envelope offset frequency of the individual lines contained in the associated frequency comb. The aim of the disclosure is to determine the carrier envelope offset frequency and to utilize said frequency to operate an acousto-optical frequency shifter (13). In said shifter, the uncompensated train of temporally equidistantly short laser pulses is diffracted in a first order such that the individual lines of the frequency comb are shifted by the carrier envelope offset frequency. The resulting compensated train of short laser pulses has a frequency comb, the individual lines of which are integral multiples of the repetition frequency of the individual light pulses in the train of short laser pulses.

Abstract: A device for increasing the spectral bandwidth of optical pulses, comprises a hollow fiber waveguide, optical components for focusing the beam into the hollow fiber waveguide and for re-collimating the beam at the exit of the hollow fiber waveguide, the hollow fiber waveguide being contained in an air-tight chamber filled with a gas at a given pressure; the length of the hollow fiber is such that, for a given input pulse energy and gas pressure, the energy contained in a fundamental propagation mode of the optical pulses that has minimum propagation losses exhibits substantially periodic oscillations over the full length of the hollow fiber waveguide and reaches a local maximum at the output end of the said hollow fiber waveguide.

Abstract: The present disclosure relates to a laser crystal device (1) for short pulse lasers, comprising a container (4), the interior of which is sealed relative to the environment and which contains a technically pure atmosphere with windows (12, 13) in the side walls (12, 13) for the passage of laser radiation (16), which in operation passes through a laser crystal (6), wherein the window (12, 13) has an inclination of the Brewster angle to the beam path of the laser radiation (16) and a mounting (5) for the laser crystal (6) is provided within the container (4), the windows (12, 13) are inclined to each other by double the Brewster angle and are placed at an adequate distance from the laser crystal (6) position, with relation to the laser beam properties, wherein the beam cross section at the windows (12, 13) is sufficiently large in order to guarantee a peak intensity at the windows (12, 13) which is sufficiently reduced in relation to the peak intensity of the laser beam (16) at the laser crystal (6) for avoidin

Abstract: A mode-locked short pulse laser resonator including a pump laser beam input, a non-linear laser medium, a plurality of resonator mirrors as well as a first outcoupler mirror and a second outcoupler mirror, wherein the first outcoupler mirror is arranged for coupling out laser radiation having first spectral properties, and the second outcoupler mirror is arranged for coupling out laser radiation having second spectral properties which are different from the first spectral properties.

Abstract: A short pulse laser arrangement with, preferably, passive mode-locking, comprising a resonator containing a laser crystal and several mirrors, one of which forms a pump beam coupling-in mirror and one of which forms a laser beam out-coupling mirror, and a multiple reflexion telescope enlarging the resonator length, the resonator in operation having a positive averaged dispersion over a wavelength range concerned; the adjustment of the positive averaged dispersion of the resonator is effected by means of the mirrors of the resonator, at least a few of which are designed as dispersive mirrors.

Abstract: Method and device for the generation of a comb of stabilized frequency lines and/or a train of ultrashort laser pulses for stabilization of the position of the carrier wave with respect to the amplitude envelope of few cycles laser pulses. Interference between spectral components generated by means of difference frequency generation and self phase modulation in one and the same non-linear crystal (4) allows detecting and stabilizing the temporal evolution of the carrier-envelope offset (CEO) phase. The described technique improves dramatically the accuracy of the stabilization and has very small insertion losses.

Abstract: The invention relates to a short-pulse laser device (11) with a preferably passive mode coupling. Said device comprises a resonator (12) which contains a laser crystal (14) in addition to several mirrors (M1-M7, OC) that define a long resonator arm (17) and a short resonator arm (16), one (M1) of said mirrors forming a pump beam coupling-in mirror and another (OC) forming a laser beam output coupler and comprising a multiple reflection telescope (18) that increases the length of the resonator and is allocated to the resonator arms (16, 17). Said telescope is constructed using mirrors (25, 26), in order to reflect a laser beam (15) that is coupled into the space between them back and forth several times, prior to being decoupled back into the other resonator, whereby sequential eccentric reflection points (1 to 8; 1? to 8?) on the mirrors (25, 26) are offset in relation to one another.

Abstract: A dispersive multilayer mirror (1) comprising several individual layers (2, 3) applied to a carrier substrate (4) and adjoining each other via parallel, plane surfaces having different optical constants and different thicknesses, wherein a wedge-shaped glass platelet (5) is fastened to the outermost individual layer (2) facing away from the carrier substrate (4) by optical contact.

Abstract: A dental laser arrangement switchable between different modes of operation, the arrangement including a laser device operable as a laser oscillator and as a laser amplifier. The laser device includes a laser resonator having a pump unit and an active modelocker as well as an optic loss element that introduces selective losses in the resonator. The laser arrangement further includes a laser beam-out-coupling unit. The modelocker is connected to a control circuit for switching between a CW-mode of operation for coagulating soft tissue, in which the modelocker is switched off, and two short-pulse modes of operation in which high frequency signals of equal frequencies, but different powers are applied by the control circuit to the modelocker so as to generate laser pulses of a pre-determined duration.

Abstract: The invention relates to a device for generating terahertz (THz) radiation comprising a short pulse laser (1) with mode coupling to which a pump beam (3) is supplied, and comprising a semiconductor component equipped with a resonator mirror (M4). This semiconductor component serves to derive the THz radiation based on incident laser pulses. The resonator mirror (M4), preferably a resonator end mirror, is provided with a semiconductor layer (8), which is partially transparent to the laser radiation of the short pulse laser (1), whose absorption edge is lower than the energy of the laser radiation of the short pulse laser (1) and on which the electrodes (9, 10) that can be connected to a bias voltage source are placed in order to generate and radiate the THz radiation in the electric field.

Abstract: A cooling device for an optical amplifier or oscillator has Peltier elements enclosed in a housing with an optical crystal and extract heat from the optical crystal. The housing is sealed and can contain a desiccant for removing moisture and preventing particle deposition. Alternately, the housing can be evacuated with a vacuum to maintain a clean operating environment. The housing holds a Brewster window at a Brewster angle with an inident laser beam to permit passage of the laser beam. The housing also can be arranged on a platform providing liquid cooling.

Abstract: The invention relates to a short-pulse laser device (11) with a preferably passive mode coupling. Said device comprises a resonator (12) which contains a laser crystal (14) in addition to several mirrors (M1-M7, OC) that define a long resonator arm (17) and a short resonator arm (16), one (M1) of said mirrors forming a pump beam coupling-in mirror and another (OC) forming a laser beam output coupler and comprising a multiple reflection telescope (18) that increases the length of the resonator and is allocated to the resonator arms (16, 17). Said telescope is constructed using mirrors (25, 26), in order to reflect a laser beam (15) that is coupled into the space between them back and forth several times, prior to being decoupled back into the other resonator, whereby sequential eccentric reflection points (1 to 8; 1? to 8?) on the mirrors (25,26) are offset in relation to one another.

Abstract: A multilayer mirror (1), in particular a multilayer dispersive mirror, comprising several individual layers (2, 3) of different properities applied to a substrate (4; 14) and following each other via parallel, plane interfaces (6), and a plane front face (5; 5?) on the side of beam impact which is inclined relative to the interfaces (6) between the individual layers (2, 3).

Abstract: A Laser arrangement (1) comprising a pump unit (2) containing a pumped laser crystal (3), and means, such as a saturable absorber (15), for passive mode-locking, wherein two separate, alternatively switchable resonator arms (11, 12) are provided, one resonator arm (11) of which, which is active in a pulse forming phase (21), comprises the saturable absorber (15), whereas the other resonator arm (12), which is active in an amplifying phase (22), is free from components that introduce losses.

Abstract: A focussing arrangement, in particular for laser devices (1), comprising a focussing mirror (M1) arranged on a carrier which is displaceable in one plane, and having a spherical reflecting surface (43), wherein the displaceable carrier is formed by a rocking member (10) which is at least approximately Z-shaped when seen in top view, the rocking member having a rocking longitudinal arm (27) which is articulately connected on both ends to transverse arms (25, 26), the longitudinal arm carrying the focussing mirror (M1), wherein the transverse arms (25, 26) are arranged so as to be pivotable about pivot axes perpendicular to the plane of displacement, and wherein the center of curvature (M) of the spherical reflecting surface (43) of the focussing mirror (M1) lies at least substantially on an axis extending through the geometric center of the longitudinal arm (27), perpendicular to the plane of displacement.