Patents Assigned to FRIEDRICH-SCHILLER-UNIVERSITAT JENA
  • Patent number: 9880446
    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.
    Type: Grant
    Filed: October 28, 2014
    Date of Patent: January 30, 2018
    Assignees: FRIEDRICH-SCHILLER-UNIVERSITAT JENA, FRAUNHOFER-GESELLSCHAFT ZUR FORDERUNG DER ANGEWANDTEN FORSCHUNG E.V.
    Inventors: Thomas Gottschall, Jens Limpert, Andreas Tunnermann, Martin Baumgartl
  • Patent number: 9815262
    Abstract: The invention relates to a method of joining substrates. It is the object of the invention in this respect to join substrates of substrate materials together without having to exert an increased effort for a coating with additional coating processes to be carried out and to be able to achieve a good quality of the join connection in so doing. In the method in accordance with the invention a pretreatment of at least one join surface of a substrate to be joined is carried out in low pressure oxygen plasma prior to the actual joining. On the joining, a contact force acts on the substrates to be joined in the range 2 kPa to 5 MPa and in this process a heat treatment is carried out at an elevated temperature of at least 100° C. and at under pressure conditions of a maximum of 10 mbar, preferably <10?3 mbar.
    Type: Grant
    Filed: February 21, 2012
    Date of Patent: November 14, 2017
    Assignees: Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V., Friedrich-Schiller-Universität Jena
    Inventors: Gerhard Kalkowski, Carolin Rothhardt, Mathias Rohde, Ramona Eberhardt
  • Publication number: 20170302047
    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).
    Type: Application
    Filed: October 1, 2015
    Publication date: October 19, 2017
    Applicants: Fraunhofer-Gesellschaft zur Forderung der angewandten Forschung e.V., Friedrich-Schiller-Universitat Jena
    Inventors: Cesar Jauregui Misas, Andreas Tunnermann, Jens Limpert, Christian Gaida
  • Publication number: 20170179666
    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.
    Type: Application
    Filed: February 3, 2015
    Publication date: June 22, 2017
    Applicants: Fraunhofer-Gesellschaft zur Forderung der angewandten Forschung e.V., Friedrich-Schiller-Universitat Jena
    Inventors: Arno Klenke, Jens Limpert, Hans-Jurgen Otto, Andreas Tunnermann
  • Patent number: 9517009
    Abstract: A method for non-invasive observations of a fundus using an ophthalmoscope is provided. The method includes illuminating a retinal region of an eye by projecting an illumination pattern of illumination light onto the retinal region, at least one of detecting a portion of fluorescent light emitted from the retinal region and detecting a portion of illumination light reflected from the retinal region, thereby capturing a series of images of the retinal region at a plurality of different relative positions of the retinal region with respect to the illumination pattern projected onto the retinal region, wherein between the capturing of at least two images of the series the relative position of the retinal region with respect to the illumination pattern projected onto the retinal region is shifted in a non-controlled manner, and processing the captured images to extract a sub-resolution image of the retinal region.
    Type: Grant
    Filed: September 26, 2013
    Date of Patent: December 13, 2016
    Assignees: Ruprecht-Karls-Universität Heidelberg, Friedrich-Schiller-Universität Jena
    Inventors: Christoph Cremer, Gerrit Best, Roman Amberger, Rainer Heintzmann, Stefan Dithmar, Thomas Ach
  • Publication number: 20160320687
    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.
    Type: Application
    Filed: October 28, 2014
    Publication date: November 3, 2016
    Applicants: Fraunhofer-Gesellschaft zur Forderung der angewand ten Forschung e.V., Friedrich-Schiller-Universitat Jena
    Inventors: Thomas Gottschall, Jens Limpert, Andreas Tunnermann, Martin Baumgartl
  • Patent number: 9296161
    Abstract: The invention relates to a method for producing an optical assembly, comprising at least two optical functional surfaces arranged in a fixed positional relationship to one another on a common supporting structure, wherein by means of a processing machine, in various process steps, at least two optical functional surfaces and at least one reference structure having a defined and measurable relative position to the optical functional surfaces are produced. The supporting structure remains rigidly connected to the processing machine until said process steps have been completed, and wherein the optical functional surfaces are then measured relative to the at least one reference structure, and any deviation from a target shape and target position is determined, after which said process steps are repeated at least once with modified actuation of the processing machine. The invention further relates to an optical device comprising an optical assembly produced in this way and to a unit for carrying out such a method.
    Type: Grant
    Filed: September 13, 2010
    Date of Patent: March 29, 2016
    Assignees: Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V., Friedrich-Schiller-Universität Jena
    Inventors: Sebastian Scheiding, Stefan Risse, Andreas Gebhardt, Christoph Damm, Thomas Peschel, Ralf Steinkopf
  • Patent number: 9235106
    Abstract: The invention relates to a method and corresponding devices for reducing mode instability in an optical waveguide (1), a light signal becoming unstable in the optical waveguide (1) 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 (2) along the optical waveguide (1) and/or a reduction in changes in the optical waveguide (1) that are caused by spatial temperature variation as a result of mode interference.
    Type: Grant
    Filed: April 12, 2013
    Date of Patent: January 12, 2016
    Assignees: FRAUNHOFER-GESELLSCHAFT ZUR FÖRDERUNG DER ANGEWANDTEN FORSCHUNG e.V., FRIEDRICH-SCHILLER-UNIVERSITÄT JENA
    Inventors: César Jáuregui Misas, Hans-Jürgen Otto, Fabian Stutzki, Florian Jansen, Tino Eidam, Jens Limpert, Andreas Tünnermann
  • Publication number: 20150298264
    Abstract: An assembly comprising: two ceramic bodies, which are joined by means of a joint of an active hard solder, or braze, wherein the active hard solder, or braze, has a continuous core volume, which is spaced, in each case, from the ceramic bodies by at least 1 ?m, and an average composition CK with a liquidus temperature Tl(CK), wherein the composition CK has a coefficient of thermal expansion ?(CK), wherein ?(CK)=m·?(K), wherein m?1.5, especially m?1.3 and preferably m?1.2, wherein ?(K) is the average coefficient of thermal expansion of the ceramic material of the ceramic bodies, wherein the joint has boundary layers, which border on the ceramic body, wherein at least one of the boundary layers, which lies outside of the core volume, has an average composition CB with a liquidus temperature Tl(CB), which lies not less than 50 K, preferably not less than 100 K, and especially preferably not less than 200 K, under the liquidus temperature Tl(CK) of the average composition CK of the core volume.
    Type: Application
    Filed: October 28, 2013
    Publication date: October 22, 2015
    Applicant: Friedrich-Schiller-Universitat Jena
    Inventors: Andreas Rossberg, Elke Schmidt, Markus Rettenmayr, Peter Siegmund
  • Publication number: 20150063767
    Abstract: The invention relates to a method and corresponding devices for reducing mode instability in an optical waveguide (1), a light signal becoming unstable in the optical waveguide (1) 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 (2) along the optical waveguide (1) and/or a reduction in changes in the optical waveguide (1) that are caused by spatial temperature variation as a result of mode interference.
    Type: Application
    Filed: April 12, 2013
    Publication date: March 5, 2015
    Applicants: FRAUNHOFER-GESELLSCHAFT ZUR FÖRDERUNG DER ANGEWANDTEN FORSCHUNG e.V., FRIEDRICH-SCHILLER-UNIVERSITÄT JENA
    Inventors: César Jáuregui Misas, Hans-Jürgen Otto, Fabian Stutzki, Florian Jansen, Tino Eidam, Jens Limpert, Andreas Tünnermann
  • Publication number: 20140083597
    Abstract: The invention relates to a method of joining substrates. It is the object of the invention in this respect to join substrates of substrate materials together without having to exert an increased effort for a coating with additional coating processes to be carried out and to be able to achieve a good quality of the join connection in so doing. In the method in accordance with the invention a pretreatment of at least one join surface of a substrate to be joined is carried out in low pressure oxygen plasma prior to the actual joining. On the joining, a contact force acts on the substrates to be joined in the range 2 kPa to 5 MPa and in this process a heat treatment is carried out at an elevated temperature of at least 100° C. and at under pressure conditions of a maximum of 10 mbar, preferably <10?3 mbar.
    Type: Application
    Filed: February 21, 2012
    Publication date: March 27, 2014
    Applicants: Friedrich-Schiller-Universität Jena, FRAUNHOFER-GESELLSCHAFT zur Förderung der angewandten Forschung e.V.
    Inventors: Gerhard Kalkowski, Carolin Rothhardt, Mathias Rohde, Ramona Eberhardt
  • Patent number: 8625644
    Abstract: The invention relates to a Q-switched laser comprised of a pump light source (1), an optical resonator accommodating a laser medium (6), and a passive Q-switch (5). 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 (8) part of the light coupled out of the optical resonator is passed on to an optical delay line (9) and coupled back into the optical resonator upon having passed through the optical delay line (9).
    Type: Grant
    Filed: September 17, 2010
    Date of Patent: January 7, 2014
    Assignees: Fraunhofer-Gesellschaft zur Forderung der Angewandten Forschung E.V., Friedrich-Schiller-Universitat Jena
    Inventors: Andreas Tünnermann, Dirk Nodop, Alexander Steinmetz, Jens Limpert
  • Publication number: 20120236400
    Abstract: The invention relates to a method for producing an optical assembly, comprising at least two optical functional surfaces arranged in a fixed positional relationship to one another on a common supporting structure, wherein by means of a processing machine, in various process steps, at least two optical functional surfaces and at least one reference structure having a defined and measurable relative position to the optical functional surfaces are produced. The supporting structure remains rigidly connected to the processing machine until said process steps have been completed, and wherein the optical functional surfaces are then measured relative to the at least one reference structure, and any deviation from a target shape and target position is determined, after which said process steps are repeated at least once with modified actuation of the processing machine. The invention further relates to an optical device comprising an optical assembly produced in this way and to a unit for carrying out such a method.
    Type: Application
    Filed: September 13, 2010
    Publication date: September 20, 2012
    Applicant: Friedrich-Schiller-Universitat Jena
    Inventors: Sebastian Scheiding, Stefan Risse, Andreas Gebhardt, Christoph Damm, Thomas Peschel, Ralf Steinkopf
  • Patent number: 8217136
    Abstract: New thieno[3,4-b]pyrazine copolymers are prepared by reacting 5,7-functionalized thieno[3,4-b]pyrazines with substituted aromatics in the presence of solvents, bases and polymerization catalysts, the copolymers thus prepared being employed preferably in the production of photovoltaic cells.
    Type: Grant
    Filed: March 22, 2007
    Date of Patent: July 10, 2012
    Assignees: Thüringisches Institut für Textil-und Kunststoff-Forschung E.V., Friedrich Schiller Universität Jena
    Inventors: Steffi Sensfuss, Maher Al Ibrahim, Lars Blankenburg, Elisabeth Klemm, Raja Shahid Ashraf, Munazza Shahid
  • Publication number: 20120069428
    Abstract: The invention relates to an optical fiber as an optical waveguide for the single-mode operation. The present invention proposes a fiber having a microstructure, by which the propagation of modes of a higher order are selectively suppressed in the optical waveguide. At the same time, the propagation of transversal modes of a higher order is dampened more strongly than the propagation of the fundamental modes of the optical waveguide.
    Type: Application
    Filed: March 12, 2010
    Publication date: March 22, 2012
    Applicants: FRIEDRICH-SCHILLER-UNIVERSITÄT JENA, FRAUNHOFER-GESELLSCHAFT ZUR FÖRDERUNG DER ANGEWANDTEN FORSCHUNG E.V.
    Inventors: Jens Limpert, Fabian Roeser, Tino Eidam, César Jáuregui Misas, Andreas Tuennermann
  • Publication number: 20110222178
    Abstract: The present invention relates to the production of an adaptive deformable mirror for compensation of defects of a wavefront.
    Type: Application
    Filed: March 17, 2009
    Publication date: September 15, 2011
    Applicants: FRAUNHOFER-GESELLSCHAFT ZUR FORDERUNG DER ANGEWANDTEN FORSCHUNG E.V., FRIEDRICH-SCHILLER-UNIVERSITAT JENA
    Inventors: Claudia Bruchmann, Erik Beckert, Thomas Peschel, Christoph Damm, Sylvia Gebhardt
  • Publication number: 20090142809
    Abstract: The invention relates to a method for cleaving cervimycin esters. An object of the invention to convert in a simple manner the cervimycin esters which are less active but formed in larger quantity into the highly active cervimycin K that occurs as a minor component in the preparation by fermentation, is achieved by preparing unesterified cervimycins from cervimycin esters with di- or monomethylated malonic acids, by ester cleavage effected by at least one esterolytic enzyme at temperatures of 20° C. to 75° C. and a pH of pH 5.0 to 10.0, preferably pH 6.0 to 9.0.
    Type: Application
    Filed: September 25, 2006
    Publication date: June 4, 2009
    Applicants: LEIBNIZ-INSTITUT FÜR NATURSTOFF-FORSCHUNG UND INFE, FRIEDRICH-SCHILLER-UNIVERSITÄT JENA
    Inventors: Uwe Horn, Armin Siering, Gundela Peschel, Christian Hertweck, Peter-Jurgen Muller, Bettina Bardl, Jorg-Hermann Ozegowski, Kerstin Herold
  • Patent number: 6371615
    Abstract: A method and apparatus for determining fluorophores on objects, especially on the living ocular fundus, which makes it possible to reliably distinguish at least partially overlapping fluorophores of objects in excitation and/or fluorescence spectra even if fluorescence intensities are very low and to select them for analysis, and optionally create a two-dimensional representation. The object (4), e.g., the ocular fundus for ophthalmological examinations, is illuminated point to point with a pulsed laser (1) and excited to autofluorescence with two-dimensional extension. The transient fluorescence light created after excitation by each laser pulse is detected in time-correlated individual photon counting (11). From the time behavior of the fluorescence light determined by individual photon counting for each site of autofluorescence, the fluorescence decay time constants are calculated, and conclusions are drawn therefrom regarding the excited fluorophores in the object (4).
    Type: Grant
    Filed: May 1, 2000
    Date of Patent: April 16, 2002
    Assignee: Friedrich-Schiller-Universität Jena Buero für Furschungstransfer-Sachgebiet Schutzrechte
    Inventors: Dietrich Schweitzer, Achim Kolb, Martin Hammer, Eike Thamm