Fraunhofer-gesellschaft Zur Foerderung Der Angewandten Forschung E.v.

Friedrich-schiller-universitat Jena

Wavelight Ag

Leibniz-institut Fur Photonische Technologien E.v.

Friedrich-schiller-universitat

Andreas Tünnermann

Jens Limpert

César Jáuregui Misas

Thomas Gottschall

Klaus Wolfgang Vogler

Frank Wippermann

Jacques Duparré

Thomas Peschel

Jens Ulrich Thomas

Florian Jansen

Gerhard Kalkowski

Stefan Nolte

Jürgen Popp

Ramona Eberhardt

Arno Klenke

Michael Müller

Fabian Stutzki

Thomas Schreiber

Tino Eidam

Enrico Seise

César Jauregui Misas

Dirk Nodop

Damian Schimpf

Christoph Stihler

Tobias Meyer

Alexander Steinmetz

Hans Jurgen Otto

Christian Gaida

Hans-Jurgen Otto

Martin Baumgartl

Tobias Meyer-Zedler

Marco Kienel

Hans-Jürgen Otto

Christian Voigtländer

Steffen Hädrich

Steffen Böhme

César JÁUREGUI Misas

Fabian Röser

Damian N Schimpf

Jan Rothhardt

Michael MÜLLER

César Misas Jauregui

Robert Williams

César JÀUREGUI Misas

Jens Prof Limpert

Carsten K Nielsen

Bülend Ortac

A device includes a plurality of imaging optical channels inclined in relation to one another, each of which includes an optic and at least one detector pixel arrangement. The plurality of optical channels are configured to obtain an image of a dot pattern of a field of view by imaging said field of view. The optical channels pass through the display plane and are set up for imaging (projecting) the field of view between the display pixels. The device includes an evaluator that is coupled to detector pixels of the detector pixel arrangements and configured to evaluate the dot pattern on the basis of a comparison, which causes hyper resolution, of signal intensities of different detector pixels so as to obtain an evaluation result, and to control the device at least partly on the basis of the evaluation result.

Device and method of capturing a projected dot pattern in a display device

The invention relates to an optical waveguide with two or more light-guiding cores (-) extending continuously along the longitudinal extension of the optical waveguide, parallel to one another and spaced apart from one another, from one end of the optical waveguide to the other, and with a first cladding () enclosing the cores (-). It is an object of the invention to provide a multicore optical waveguide for high-power operation with reduced system complexity compared to the prior art. This object is achieved by the invention in that the cores (-) are arranged relative to one another and are spaced apart from one another in such a way that the propagation modes of the light propagating in the optical waveguide at a working wavelength couple to one another, the length of the optical waveguide being selected such that the light coupled into only a single one of the cores (-) at one end of the optical waveguide first spreads to the other cores (-) during propagation through the optical waveguide and, after passing through the optical waveguide, leaves the optical waveguide again at the other end from a single core () with at least 60%, preferably at least 75%, of the total light power propagating in the optical waveguide. The invention also relates to a laser system with such an optical waveguide as an optical amplifier, and a method for guiding light in an optical waveguide.

Optical waveguide

A device for generating laser pulses is provided, the device having an optical parametric oscillator converts the laser pulses of a pump laser to laser pulses at a signal wavelength and at an idler wavelength. The optical parametric oscillator has an optical resonator with a non-linear wavelength converter. It is an object of the invention to provide a device that makes efficient generation of synchronous laser pulse trains with two different central wavelengths possible. To this end, the invention proposes that the pump laser is tunable with respect to the pump wavelength and the repetition frequency, wherein the resonator has an optical fibre with a dispersion in the range of 10-100 ps/nm and a length of 10-1000 m. The invention furthermore relates to a method for generating laser pulses using such a device.

Device and method for generating laser pulses

The invention relates to a method for stably transmitting laser radiation through an optical waveguide (), wherein two or more modes of the laser radiation propagating in the optical waveguide () interfere and form a mode interference pattern in the optical waveguide, as a result of which a thermally induced refractive index grating is produced in the optical waveguide (). It is an object of the invention to demonstrate an effective approach for stabilizing the output signal of the optical waveguide () in a fiber-based laser/amplifier combination at high output powers, i.e. for avoiding mode instability. The invention achieves this object by virtue of the fact that a relative spatial phase shift between the mode interference pattern and the thermally induced refractive index grating is set in the direction of propagation of the laser radiation. In addition, the invention relates to a laser/amplifier combination comprising a laser () and an optical waveguide () in the form of an amplifier fiber, wherein the optical waveguide () amplifies the radiation of the laser () propagating therein. The invention proposes an actuating element (), which produces a predefinable relative spatial phase shift of the mode interference pattern and of the thermally induced refractive index grating in the direction of propagation of the laser radiation.

Avoiding mode instability in an optical amplifier fiber

The invention relates to an apparatus for generating laser pulses. It is an object of the invention to provide a method for generating synchronized laser pulse trains at variable wavelengths (e.g., for coherent Raman spectroscopy/microscopy), wherein the switching time for switching between different wavelengths should be in the sub-&#x3bc;s range. For this purpose the apparatus according to the invention comprises

Generating synchronized laser pulses at variable wavelengths

The invention relates to an optical arrangement having

Optical arrangement

The invention relates to an optical waveguide () as a laser medium or as a gain medium for high-power operation, wherein the optical waveguide () 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 () 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 () in a laser/amplifier combination.

Optical waveguide as amplifier fibre for high-performance operation

The invention relates to an optical waveguide with at least one core region () extending along the longitudinal extent of the optical waveguide, and with a first jacket () which, viewed in the cross section of the optical waveguide, surrounds the core region (). 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 ().

The invention relates to an optical array comprising a splitting element () which splits an input beam (E) into at least two partial beams (T, T, T, T), at least one optical element (V, V, V, V, MV) through which at least one of the partial beams (T, T, T, T) propagates, and at least one combining element () which spatially superimposes the partial beams (T, T, T, T) 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 () and/or the combining element () each have a partially reflective element (') which reflects the radiation of the input beam (E) or of the output beam (A) two or more times, wherein the partially reflective element (&#x2032;) has zones (a, b, c, d) of different reflectivity.

Optical array comprising a beam splitter

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

Apparatus and method for producing short radiation pulses

The invention relates to a method and corresponding devices for reducing mode instability in an optical waveguide (), a light signal becoming unstable in the optical waveguide () 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 () along the optical waveguide () and/or a reduction in changes in the optical waveguide () that are caused by spatial temperature variation as a result of mode interference.

Method and device for reducing mode instability in an optical waveguide

The invention relates to a Q-switched laser comprised of a pump light source (), an optical resonator accommodating a laser medium (), and a passive Q-switch (). It is the object of the present invention to provide an improved Q-switched laser which is of a simple and compact setup while having the least possible jitter of the repetition time. To achieve this target, the invention proposes that by means of a beam splitter () part of the light coupled out of the optical resonator is passed on to an optical delay line () and coupled back into the optical resonator upon having passed through the optical delay line ().

Stabilisation of the repetition rate of a passively Q-switched laser by means of coupled resonators

An apparatus for laser processing of a material, in particular the eye cornea, emits on to the material a train (') 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 (&#x2032;). 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 (&#x2032;) has substantially lower intensity or energy than a following main pulse (&#x2032;).

Apparatus and method for laser treatment of a biological material

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Weimar, Germany

Andreas Tünnermann