Patents by Inventor Guenter Hollemann

Guenter Hollemann has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 10312659
    Abstract: This disclosure provides methods and apparatuses which advantageously stabilize beam parameters and elongate crystal lifetime. In one aspect, a UV laser apparatus includes a non-linear crystal, a laser source, a beam-crystal displacer, a beam parameter monitor, and a laser control unit. The laser source directs a source beam to the non-linear crystal to produce a UV beam and the beam-crystal displacer shifts the non-linear crystal relative to the source beam at a plurality of shift speeds. The beam parameter monitor measures the UV beam and outputs a measurement of a beam parameter. The laser control unit: receives the measurement; determines, based on the measurement, an adjustment in shift speed that steers the beam parameter toward a target value; and outputs the adjustment to the beam-crystal displacer.
    Type: Grant
    Filed: March 20, 2018
    Date of Patent: June 4, 2019
    Assignee: COHERENT LASERSYSTEMS GMBH & CO. KG
    Inventors: Guenter Hollemann, Axel Kneip
  • Publication number: 20100226396
    Abstract: In an optical arrangement for pumping solid-state lasers, there is the object of producing an intensity distribution across the beam cross section of the pump radiation with a rectangular intensity profile, which intensity distribution is homogeneous at least in a region corresponding to the Rayleigh range in the direction of the beam propagation without the beam quality being substantially impaired by the homogenization. The pump arrangement contains a rod-shaped homogenizer (1) with two opposed, polished end faces (2,3), planar side limit faces (4), which are arranged parallel to the optical axis and with a cross-sectional area at right angles to the optical axis, which forms a regular polygon, with the regular polygon being restricted to those number of sides which permit a plurality of polygons to be positioned against one another on a surface in such a way that they fill the space.
    Type: Application
    Filed: July 20, 2007
    Publication date: September 9, 2010
    Inventor: Guenter Hollemann
  • Patent number: 7573930
    Abstract: A laser system, which is used in material processing to produce a radiation line of small width and uniform high intensity in the longitudinal direction, produces radiation that has different mode numbers M2 perpendicular to the propagation direction.
    Type: Grant
    Filed: June 14, 2007
    Date of Patent: August 11, 2009
    Assignee: Innovavent GmbH
    Inventors: Günter Hollemann, Peter Heist, Peter Oesterlin, Berthold Burghardt, Hans-Jürgen Kahlert, Klaus Brunwinkel, Henning Schmidt, Thomas Gabler, Ulf Krause
  • Patent number: 7463658
    Abstract: A laser for generating pulsed laser radiation. An element is arranged in the resonator to generate laser radiation having the first wavelength by frequency conversion of the primary radiation. The resonator is switchable into a first state in which it is open to the primary radiation, and a second state in which it is closed to the primary radiation, and is open to laser radiation of the first wavelength in both states. A control unit switches the resonator from the first to the second state so that the primary radiation begins to oscillate and the pulse generation by frequency conversion begins, switches the resonator from the second to the first state, whereby primary radiation is coupled out from the resonator. It is possible to set the duration between both steps and/or the coupling-out behavior of the resonator to adjust the pulse duration via the control unit.
    Type: Grant
    Filed: February 13, 2007
    Date of Patent: December 9, 2008
    Assignee: JENOPTIK Laser, Optik, Systeme GmbH
    Inventors: Guenter Hollemann, Peter Heist, Adolf Giesen, Christian Stolzenburg
  • Publication number: 20080253407
    Abstract: A laser for generating pulsed laser radiation is provided. The laser includes a resonator, a laser-active medium arranged in the resonator, and an acousto-optic modulator arranged in the resonator. The modulator can be put in a first and a second state so as to set the resonator quality, the resonator quality being lower in the first state than in the second state, and comprising a control unit for controlling the modulator. The control unit effects phase-locked coupling of a high-frequency signal to be applied to the modulator in one of said two states, in order to generate a predetermined sound field in the modulator, and a switching signal designed to switch the modulator periodically between the two states.
    Type: Application
    Filed: April 11, 2008
    Publication date: October 16, 2008
    Applicant: JENOPTIK LASER, OPTIK, SYSTEME GMBH
    Inventors: Guenter Hollemann, Peter Heist, Matthias Hoffmann
  • Publication number: 20080031290
    Abstract: A laser for generating pulsed laser radiation. An element is arranged in the resonator to generate laser radiation having the first wavelength by frequency conversion of the primary radiation. The resonator is switchable into a first state in which it is open to the primary radiation, and a second state in which it is closed to the primary radiation, and is open to laser radiation of the first wavelength in both states. A control unit switches the resonator from the first to the second state so that the primary radiation begins to oscillate and the pulse generation by frequency conversion begins, switches the resonator from the second to the first state, whereby primary radiation is coupled out from the resonator. It is possible to set the duration between both steps and/or the coupling-out behavior of the resonator to adjust the pulse duration via the control unit.
    Type: Application
    Filed: February 13, 2007
    Publication date: February 7, 2008
    Inventors: Guenter Hollemann, Peter Heist, Adolf Giesen, Christian Stolzenburg
  • Patent number: 7286576
    Abstract: The object of a pulsed laser arrangement and a method for adjusting the pulse length of laser pulses is to change the pulse length over a wide range substantially independent from the laser output power, in particular to counteract a reduction in output and to prevent a negative change in the beam parameters when lengthening the pulse by means of varying the oscillator output. A multistage laser amplifier in which an amplifying medium with a small-signal amplification of more than 10 is provided in every stage (17-22) is arranged downstream of a diode-pumped Q-switched solid state laser oscillator with variable oscillator output for supplying oscillator pulses. The total small-signal amplification brought about by all of the amplifying media is greater than 1000. The pulsed laser arrangement and the method can be used for industrial and medical purposes requiring pulse lengths in the range of several hundred ns to several ?s at pulse repetition rates between 10 kHz and 200 kHz.
    Type: Grant
    Filed: July 10, 2003
    Date of Patent: October 23, 2007
    Assignee: Jenoptik Laser, Optik, Systeme GmbH
    Inventors: Guenter Hollemann, Martin Leitner, Jan Symanowski
  • Publication number: 20070030878
    Abstract: In a laser arrangement and a method for generating a multimode operation with intracavity frequency doubling, the object of the invention is to eliminate fluctuations in output caused by the nonlinear coupling between the longitudinal modes due to sum frequency generation in a simple laser construction which has increased thermal and mechanical stability. Two multimode spectral regions are situated in the edge areas of the spectral gain region of a disk-shaped gain medium within which longitudinal modes have no gain advantage among one another for spatial hole burning, and in which oscillation of one of the two multimode spectral regions is prohibited.
    Type: Application
    Filed: May 18, 2006
    Publication date: February 8, 2007
    Inventors: Guenter Hollemann, Stefan Knoke
  • Publication number: 20060126676
    Abstract: The object of a pulsed laser arrangement and a method for adjusting the pulse length of laser pulses is to change the pulse length over a wide range substantially independent from the laser output power, in particular to counteract a reduction in output and to prevent a negative change in the beam parameters when lengthening the pulse by means of varying the oscillator output. A multistage laser amplifier in which an amplifying medium with a small-signal amplification of more than 10 is provided in every stage (17-22) is arranged downstream of a diode-pumped Q-switched solid state laser oscillator with variable oscillator output for supplying oscillator pulses. The total small-signal amplification brought about by all of the amplifying media is greater than 1000. The pulsed laser arrangement and the method can be used for industrial and medical purposes requiring pulse lengths in the range of several hundred ns to several ?s at pulse repetition rates between 10 kHz and 200 kHz.
    Type: Application
    Filed: July 10, 2003
    Publication date: June 15, 2006
    Inventors: Guenter Hollemann, Martin Leitner, Jan Symanowski
  • Patent number: 6973108
    Abstract: The object in an arrangement for pumping an anisotropic laser crystal is to reduce the influence of the destruction limit of the laser crystal on increased pump power density and, in this connection, to achieve improved beam quality and increased efficiency of a diode-pumped solid state laser. At the same time, the pump volume and cross-sectional area are to be kept as small as possible along a length of the crystal corresponding at least approximately to the absorption length. The arrangement operates with an asymmetric pump beam whose pump beam cross section has different dimensions perpendicular to one another and with a laser beam cross section which is adapted to this asymmetry. That axis of the crystallographic axes of the anisotropic laser crystal in whose direction the highest value of the crystal breaking limit exists is oriented along the greatest temperature gradient in the direction of the smaller dimension of the pump beam cross section.
    Type: Grant
    Filed: October 10, 2002
    Date of Patent: December 6, 2005
    Assignee: JENOPTIK Laser, Optik, Systeme GmbH
    Inventors: Bernd Braun, Guenter Hollemann
  • Publication number: 20050254533
    Abstract: The invention relates to an arrangement and a method for generating ultrashort laser pulses. The aim of the invention is to avoid the deterioration of the beam quality caused by the plurality of required revolutions, the accompanying loss of revolutions, and pulse broadening in regenerative amplifiers by means of a simpler and more cost-effective laser installation, and to provide ultrashort laser pulses with pulse repeat rates in an extended kHz range. In an installation consisting of a solid-state laser oscillator, a multi-stage laser amplifier which is arranged downstream therefrom and is used to increase the energy of pulses, and at least one switching element for selecting pulses from a pulse train provided by the solid-state laser oscillator, a small-signal gain higher than 10 is provided in an amplifying laser crystal in each amplification stage, the total small-signal gain produced by all amplifying laser crystals amounting to more than 100.
    Type: Application
    Filed: August 29, 2003
    Publication date: November 17, 2005
    Inventors: Guenter Hollemann, Bernd Braun, Ulf Krause
  • Publication number: 20050117841
    Abstract: Disclosed is an optical array for generating a broadband spectrum. The aim of the invention is to reduce the technical complexity of said optical array while keeping the source of laser radiation compact and adjusting in a simple manner the wavelength range of the broadband spectrum to the sensitivity range of conventional semiconductor detectors. Said aim is achieved by coupling in an optically adapted manner a passively mode-coupled solid body laser which supplies picosecond impulses having an initial wavelength that lies within the infrared range to a photonic fiber. A radiation performance interval of the broadband spectrum, which is maintained at an essentially steady intensity, is set within a wavelength range of 700 nm to 1000 nm below the initial wavelength by adjusting the dispersion of said photonic fiber to the initial wavelength.
    Type: Application
    Filed: May 7, 2003
    Publication date: June 2, 2005
    Inventors: Bernd Braun, Guenter Hollemann
  • Patent number: 6898222
    Abstract: A diode laser arrangement is disclosed wherein a radiation source is designed which can be scaled with respect to power such that different types of cooling can be applied and the configuration of the radiation field is suitable for adapting to different tasks in a simple manner. For this purpose, every diode laser is connected to a thermal contact surface of a separate, heat-spreading carrier which is fastened to a cooling surface of a common cooling element so as to be electrically insulated. The carriers are arranged adjacently in such a way that the line-shaped emission regions of the diode lasers are adjacent in series and the p-n junction planes extend parallel to the thermal contact surfaces. The diode laser arrangement is particularly suitable as a pump light source.
    Type: Grant
    Filed: November 21, 2001
    Date of Patent: May 24, 2005
    Assignee: Jenoptik Laserdiode GmbH
    Inventors: Petra Hennig, Guenter Hollemann
  • Patent number: 6711184
    Abstract: A diode-pumped laser is disclosed with internal frequency doubling to prevent interfering power fluctuations in the laser radiation generated by the non-linear crystal at the start of the power adjustment in a simple and, therefore, inexpensive construction without power-reducing elements in the cavity or thermal effects having a negative impact on the laser behavior. The laser contains, as laser-active medium, a solid-state laser crystal with a temperature gradient directed substantially parallel to the cavity axis. The conversion of laser radiation of a fundamental laser wavelength into laser radiation of another wavelength is carried out by a non-linear optical crystal with a lower non-linear conversion efficiency than that required for achieving maximum power of the converted laser radiation. The laser can be used particularly for medical purposes, e.g., in the field of ophthalmology for coagulation of the retina as well as in the field of dermatology.
    Type: Grant
    Filed: May 18, 2001
    Date of Patent: March 23, 2004
    Assignee: JENOPTIK Laser, Optik, Systeme GmbH
    Inventors: Guenter Hollemann, Wolfram Mendler, René Beilschmidt
  • Patent number: 6661568
    Abstract: In a diode-pumped laser amplifier the inventive object is to increase the tolerance of the amplifier arrangement relative to variations of the input parameters significantly, so that fine-tuning is no longer necessary for guaranteeing the stability of the amplifier. Into a laser-active solid-state medium where a thermal lens of a strength which is different in orthogonal planes is generated in consequence of the irradiated pump radiation, a laser beam to be amplified is directed into the laser-active solid-state medium while being focused in the plane with a strong thermal lens, wherein a beam waist that is being generated lies in the area of the thermal lens. The laser amplifier can be used for amplifying the radiation of an oscillator.
    Type: Grant
    Filed: August 24, 2001
    Date of Patent: December 9, 2003
    Assignee: Jenoptik Laser, Optik Systeme GmbH
    Inventors: Guenter Hollemann, Jan Symanowski
  • Publication number: 20030099267
    Abstract: A diode laser arrangement is disclosed wherein a radiation source is designed which can be scaled with respect to power such that different types of cooling can be applied and the configuration of the radiation field is suitable for adapting to different tasks in a simple manner. For this purpose, every diode laser is connected to a thermal contact surface of a separate, heat-spreading carrier which is fastened to a cooling surface of a common cooling element so as to be electrically insulated. The carriers are arranged adjacently in such a way that the line-shaped emission regions of the diode lasers are adjacent in series and the p-n junction planes extend parallel to the thermal contact surfaces. The diode laser arrangement is particularly suitable as a pump light source.
    Type: Application
    Filed: December 26, 2002
    Publication date: May 29, 2003
    Inventors: Petra Hennig, Guenter Hollemann
  • Publication number: 20030091078
    Abstract: The object in an arrangement for pumping an anisotropic laser crystal is to reduce the influence of the destruction limit of the laser crystal on increased pump power density and, in this connection, to achieve improved beam quality and increased efficiency of a diode-pumped solid state laser. At the same time, the pump volume and cross-sectional area are to be kept as small as possible along a length of the crystal corresponding at least approximately to the absorption length. The arrangement operates with an asymmetric pump beam whose pump beam cross section has different dimensions perpendicular to one another and with a laser beam cross section which is adapted to this asymmetry. That axis of the crystallographic axes of the anisotropic laser crystal in whose direction the highest value of the crystal breaking limit exists is oriented along the greatest temperature gradient in the direction of the smaller dimension of the pump beam cross section.
    Type: Application
    Filed: October 10, 2002
    Publication date: May 15, 2003
    Applicant: JENOPTIK Laser, Optik, Systeme GmbH
    Inventors: Bernd Braun, Guenter Hollemann
  • Publication number: 20020036821
    Abstract: In a diode-pumped laser amplifier the inventive object is to increase the tolerance of the amplifier arrangement relative to variations of the input parameters significantly, so that fine-tuning is no longer necessary for guaranteeing the stability of the amplifier. Into a laser-active solid-state medium where a thermal lens of a strength which is different in orthogonal planes is generated in consequence of the irradiated pump radiation, a laser beam to be amplified is directed into the laser-active solid-state medium while being focused in the plane with a strong thermal lens, wherein a beam waist that is being generated lies in the area of the thermal lens. The laser amplifier can be used for amplifying the radiation of an oscillator.
    Type: Application
    Filed: August 24, 2001
    Publication date: March 28, 2002
    Inventors: Guenter Hollemann, Jan Symanowski
  • Patent number: 6266358
    Abstract: The invention relates to a diode-pumped solid-state laser (DSSL) comprises a pumping light source having a diode stack. The inventive laser also comprises a laser rod and a pumping cavity, whereby the pumping light source accommodated in a separate housing can be exchanged as a pumping module with simple handles. As a result, the pumping light source is protected from electrostatic discharge of the diodes, mechanical stress and from contamination. Given that it is possible to accommodate alternative pumping light sources of varying pumping capacities in the pumping module, the user can exchange the pumping module when the pumping module is worn as well as when additional power is required.
    Type: Grant
    Filed: August 23, 1999
    Date of Patent: July 24, 2001
    Assignee: Jenoptik Aktiengesellschaft
    Inventors: Guenter Hollemann, Karin Pachomis, Uwe Kutschki
  • Patent number: 6058129
    Abstract: A laser comprises an active element and two resonators wherein each resonator further comprises a highly reflective resonator element and an output coupling element which reflects the radiation of the active element in itself. The active element amplifies incident radiation from a solid angle range by a normal of the active element which is distinctly greater than zero. The resonators are arranged relative to the active element such that each resonator reflects the radiation on the active element at a different angle of incidence within the solid angle range.
    Type: Grant
    Filed: December 22, 1997
    Date of Patent: May 2, 2000
    Assignee: Jenoptik Aktiengesellschaft
    Inventors: Hermann Voelckel, Guenter Hollemann, Ralf Koch