Patents Assigned to Coherent, Inc.
  • Broad-area edge-emitting semiconductor laser with limited thermal contact
    Patent number: 8233513
    Abstract: A diode-laser having an elongated diode-laser emitter is mounted on a relatively massive heat-sink. Two parallel grooves are machined into the heat-sink to leave a relatively narrow elongated ridge of the heat-sink between the grooves. The ridge has a width about equal to or narrower that the width of the emitter. The diode-laser is mounted on the heat-sink such that thermal communication between the emitter and heat-sink is essentially limited to thermal communication with the ridge.
    Type: Grant
    Filed: April 22, 2011
    Date of Patent: July 31, 2012
    Assignee: Coherent, Inc.
    Inventors: David Schleuning, Kenneth D. Scholz
  • DRIVING CIRCUIT FOR ANALOG-MODULATED DIODE-LASER
    Publication number: 20120183005
    Abstract: A diode-laser is driven by a modulated voltage through a voltage-to-current converter. The modulated voltage has a fixed level determined by an applied fixed bias voltage and a variable level determined by a modulation voltage signal varying between minimum and maximum values. The fixed voltage level corresponds to a threshold level above which the diode-laser would provide laser-output. The modulation voltage signal is monitored and compared with a predetermined set value. If the monitored voltage signal falls below the set value, the modulated voltage is disconnected from the voltage-to-current converter and the output of the diode-laser falls to zero.
    Type: Application
    Filed: January 19, 2011
    Publication date: July 19, 2012
    Applicant: Coherent, Inc.
    Inventors: Gilbert A. Hoffman, Richard J. Farmer
  • Compensation for transient heating of laser mirrors
    Patent number: 8201954
    Abstract: A mirror assembly for a carbon dioxide (CO2) slab laser resonator includes a center section having a rectangular cross-section and a pair of thermal balancing bars. A concave reflecting surface formed on a front edge of a center section. The side-bars are attached to either side of the center section and extend forward of the reflective surface. Dimensions of the center section and side bars are selected to position the thermal neutral plane of the assembly close to the reflective surface. This minimizes changes the radius of curvature of the reflective surface due to heating by circulating radiation in the resonator.
    Type: Grant
    Filed: May 12, 2009
    Date of Patent: June 19, 2012
    Assignee: Coherent, Inc.
    Inventors: Adrian Papanide, Leon A. Newman, Lanny Laughman
  • SHORT-PULSE FIBER-LASER
    Publication number: 20120147908
    Abstract: A mode-locked fiber laser has a resonator including a gain-fiber, a mode-locking element, and a spectrally-selective dispersion compensating device. The resonator can be a standing-wave resonator or a traveling-wave resonator. The dispersion compensating device includes only one diffraction grating combined with a lens and a minor to provide a spatial spectral spread. The numerical aperture of the gain-fiber selects which portion of the spectral spread can oscillate in the resonator.
    Type: Application
    Filed: December 14, 2010
    Publication date: June 14, 2012
    Applicant: Coherent, Inc.
    Inventors: Dmitri SIMANOVSKI, Andrei STARODOUMOV
  • Arrangement for RF power delivery to a gas discharge laser with cascaded transmission line sections
    Patent number: 8199789
    Abstract: RF power is transmitted to a CO2 gas discharge laser form a source of RF power via a series combination of transmission line sections. The lengths and characteristic impedances of the transmission line sections are selected to transform the impedance of the RF power source to the operating impedance of the laser.
    Type: Grant
    Filed: April 20, 2011
    Date of Patent: June 12, 2012
    Assignee: Coherent, Inc.
    Inventors: Frederick W. Hauer, Patrick T. Tracy, R. Russel Austin
  • LINE-PROJECTION APPARATUS FOR ARRAYS OF DIODE-LASER BAR STACKS
    Publication number: 20120113996
    Abstract: In optical apparatus for illuminating a mask-plane with a line of light, a light source includes four fast-axis stacks of laser diode bars with fast and slow axis collimating arrangements providing four collimated beams of diode-laser light. A combination of a lens element and two diffraction gratings collects the four collimated beams and spreads the beams in the fast-axis direction such that the spread beams overlap in the mask plane to form a line of light having a length in the fast-axis-direction and a width in the slow-axis direction of the diode-laser bar stacks.
    Type: Application
    Filed: November 9, 2010
    Publication date: May 10, 2012
    Applicant: Coherent, Inc.
    Inventor: Nadia CAPOLLA
  • Two frequency resonantly excited MEMS mirror for diode-laser marker
    Patent number: 8174751
    Abstract: Apparatus for marking a bitmap image on tape includes a scanning mirror which is incorporated in a micro-electro-mechanical system (MEMS). The MEMS is torsionally resonant at two frequencies one being about three time the other. The MEMS is excited to resonance by applying an AC signal to the actuators, causing the mirror to oscillate. The AC signal has components at the two frequencies. The magnitude and phase-relationship of the components can be selected such that the mirror oscillates in an approximation of a triangle-wave.
    Type: Grant
    Filed: April 12, 2011
    Date of Patent: May 8, 2012
    Assignee: Coherent, Inc.
    Inventor: John H. Jerman
  • Optically-pumped external-cavity surface-emitting semiconductor lasers with front-cooled gain-structures
    Patent number: 8170073
    Abstract: A semiconductor gain-structure functions as a gain-element in a laser-resonator. The gain-structure is bonded to a diamond heat-spreader that is peripherally cooled by a heat-sink configured to allow access to the gain-structure by laser-radiation circulating in the laser-resonator. In one example, the gain-structure is used as a transmissive gain-structure in a traveling-wave ring-resonator. In another example, the gain-structure surmounts mirror-structure which functions as an end-mirror of a standing-wave laser-resonator.
    Type: Grant
    Filed: September 11, 2009
    Date of Patent: May 1, 2012
    Assignee: Coherent, Inc.
    Inventors: Sergei V. Govorkov, R. Russel Austin
  • Two-dimensional diode-laser array with broad-band output
    Patent number: 8160115
    Abstract: It is demonstrated that substantial operating-parameter-dependent temperature-differences can exist between diode-laser bars in pulsed operation of a stack of such bars arranged to provide a two-dimensional array of diode-laser emitters. These differences can produce distortion of the aggregate output spectrum of the stack. By selecting particular nominal emitting wavelengths of the diode-laser bars for specific positions in the stack, the aggregate emission-spectrum can be tailored to a desired shape for one or more sets of operating parameters of the stack.
    Type: Grant
    Filed: June 26, 2009
    Date of Patent: April 17, 2012
    Assignee: Coherent, Inc.
    Inventor: David Schleuning
  • IMPEDANCE-MATCHING CIRCUITS FOR MULTI-OUTPUT POWER SUPPLIES DRIVING CO2 GAS-DISCHARGE LASERS
    Publication number: 20120086519
    Abstract: Electrical apparatus for connecting a radio frequency power-supply having two outputs to a load includes two radio frequency transmission-lines, each one connected to a corresponding power-supply output. A transformer arrangement connects the two transmission-lines to the load. Each transmission-line includes a series-connected pair of twelfth-wave transmission-line sections. The series-connection between the twelfth wave transmission-line sections in one transmission line is connected to the series-connection between the twelfth-wave transmission-line sections in the other by a device having an adjustable impedance.
    Type: Application
    Filed: February 17, 2011
    Publication date: April 12, 2012
    Applicant: Coherent, Inc.
    Inventors: Frederick W. HAUER, Joel Fontanella, Patrick T. Tracy
  • LARGE-FIELD UNIT-MAGNIFICATION CATADIOPTRIC PROJECTION SYSTEM
    Publication number: 20120063010
    Abstract: A unit magnification projection optical system includes, listed in order along a system axis, a mirror, a lens group having negative power and a lens group having positive power. The optical system is a symmetric system, with an object plane on one side of the system axis and an object plane on an opposite side of the system axis. The object and image planes are spaced apart from the positive lens group by a working distance greater than 100 millimeters.
    Type: Application
    Filed: August 30, 2011
    Publication date: March 15, 2012
    Applicant: Coherent, Inc.
    Inventor: Romeo I. Mercado
  • LINE-PROJECTION APPARATUS FOR ARRAYS OF DIODE-LASER BAR STACKS
    Publication number: 20120057345
    Abstract: In optical apparatus for illuminating a mask-plane with a line of light, a light source includes four fast-axis stacks of laser diode bars. One optical arrangement collects light beams from all of the diode-laser bar stacks, homogenizes and expands the beams in the fast-axis direction of the diode-laser bar stacks and partially overlaps the homogenized and expanded beams in the fast-axis direction. Another optical arrangement homogenizes the sum of the partially overlapped beams and images the sum of the beams as a line of light having a length in the fast-axis-direction and a width in the slow-axis direction.
    Type: Application
    Filed: December 14, 2010
    Publication date: March 8, 2012
    Applicant: Coherent, Inc.
    Inventor: Sivarama Krishna KUCHIBHOTLA
  • Detection of hidden objects by terahertz heterodyne laser imaging
    Patent number: 8129684
    Abstract: A THz-frequency heterodyne imaging method is used to remotely detect objects concealed in or under a person's clothing. One THz-frequency beam is scanned over a person being examined. A portion of the beam penetrates the persons clothing and is reflected by an object concealed under the person's clothing. The reflected portion the beam is mixed with another beam of THz-frequency radiation having a different frequency to provide a signal having an intermediate frequency (IF) including image data representative of the concealed object.
    Type: Grant
    Filed: March 22, 2005
    Date of Patent: March 6, 2012
    Assignee: Coherent, Inc.
    Inventor: Eric R. Mueller
  • COlaser output power control during warm-up
    Patent number: 8116346
    Abstract: A CO2 gas discharge laser includes a housing enclosing spaced-apart electrodes and a lasing gas. A laser resonator extends between the spaced-apart electrodes. An RF power supply provides RF power for creating a discharge in the lasing gas, causing laser radiation to be delivered by the laser resonator. The power of the output radiation is directly dependent on the RF power provided to the electrodes and inversely dependent of the temperature of the gas discharge. A signal representative of the discharge-temperature is used to adjust the RF power supplied to the electrodes such that the power of the output radiation is about constant.
    Type: Grant
    Filed: April 1, 2010
    Date of Patent: February 14, 2012
    Assignee: Coherent, Inc.
    Inventors: Gongxue Hua, Lanny Laughman
  • HERMETICALLY-SEALED RF FEED-THROUGH WITH INTEGRATED CAPACITOR
    Publication number: 20120033703
    Abstract: A carbon-dioxide (CO2) gas-discharge slab laser includes elongated discharge-electrodes in a sealed enclosure. Radio Frequency (RF) power is supplied to the electrodes via an impedance matching network and a co-axial electrical low inductance transmission line feed-through sealed to the enclosure. The feed-trough includes two spring contacts which are configured to be spring compression push-fit in grooves in edges of the discharge-electrodes. A central conductor of the feed-through is fluid cooled. A capacitor of the impedance matching network is assembled on the central conductor as an integral part of the feed-trough.
    Type: Application
    Filed: September 19, 2011
    Publication date: February 9, 2012
    Applicant: Coherent, Inc.
    Inventors: Leon A. NEWMAN, Vernon A. Seguin, Lanny Laughman, Adrian Papanide
  • OPTICAL PUMPING OF A SOLID-STATE GAIN-MEDIUM USING A DIODE-LASER BAR STACK WITH INDIVIDUALLY ADDRESSABLE BARS
    Publication number: 20120033692
    Abstract: A diode-laser bar stack includes a plurality of diode-laser bars having different temperature dependent peak-emission wavelengths. The stack is arranged such that the bars can be separately powered. This allows one or more of the bars to be “on” while others are “off”. A switching arrangement is described for selectively turning bars on or off, responsive to a signal representative of the temperature of the diode-laser bar stack, for providing a desired total emission spectrum.
    Type: Application
    Filed: August 9, 2010
    Publication date: February 9, 2012
    Applicant: Coherent, Inc.
    Inventors: David M. Schleuning, Mark M. Gitin, R. Russel Austin
  • HYBRID FIBER-MOPA
    Publication number: 20110310468
    Abstract: A master oscillator power-amplifier stages includes multiple stages of fiber-amplification with a final power amplifier stage in the form of a multi-pass amplifier. With a thin-disk gain medium in one example the thin-disk amplifier includes a common optical arrangement for providing multiple incidences of radiation to be amplified and multiple incidences of a pump-radiation beam on the thin-disk gain medium.
    Type: Application
    Filed: June 22, 2010
    Publication date: December 22, 2011
    Applicant: Coherent, Inc.
    Inventors: Michael Hertwig, Norman Hodgson, Luis A. Spinelli
  • IMPEDANCE-MATCHING TRANSFORMERS FOR RF DRIVEN CO2 GAS DISCHARGE LASERS
    Publication number: 20110285473
    Abstract: In a CO2 gas discharge laser energized by a radio frequency (RF) power source a transformer having selectively variable output impedance is used to match output impedance of the power source to the impedance of discharge electrodes of the laser. A similar transformer can be used to impose a selective variable phase-shift on the RF power from the source. The variable impedance transformer can also be used for impedance matching between amplifier stages in the power source.
    Type: Application
    Filed: May 24, 2010
    Publication date: November 24, 2011
    Applicant: Coherent, Inc.
    Inventors: Frederick W. HAUER, Patrick T. Tracy
  • Beam dump for a very-high-intensity laser beam
    Patent number: 8047663
    Abstract: A beam terminator for a high-power laser beam comprises a thermally conductive body including a beam-trapping chamber. A tapered spiral channel extends into the conductive body for guiding the beam. The beam is partially absorbed while propagating along the channel to the trapping chamber. What remains of the beam is absorbed in the trapping chamber.
    Type: Grant
    Filed: September 24, 2007
    Date of Patent: November 1, 2011
    Assignee: Coherent, Inc.
    Inventors: H. Yang Pang, Donald E. Harryman, William Clayton Brand
  • Acousto-optically Q-switched COlaser
    Patent number: 8050306
    Abstract: A pulsed CO2 laser is Q-switched by an intracavity acousto-optic (AO) Q-switch including an AO material transparent at a fundamental wavelength of the laser. In one example the AO material is germanium.
    Type: Grant
    Filed: February 3, 2011
    Date of Patent: November 1, 2011
    Assignee: Coherent, Inc.
    Inventors: Vernon A. Seguin, Peter P. Chenausky