Patents Examined by Michael T. Nguyen
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Patent number: 7386021Abstract: In a first broad aspect, the invention provides a light source. The light source includes a semiconductor laser for emitting laser light at a first frequency. The light source also includes an optical fibre that includes a fibre Bragg grating. The fibre Bragg grating is optically coupled to the semiconductor laser for receiving the laser light, reflecting a reflected portion of the laser light towards the laser and allowing the transmitted portion of the laser light to pass through the fibre Bragg grating. The fibre Bragg grating has a temperature-dependant reflection spectrum. A frequency converting optical element is optically coupled to the fibre Bragg grating for receiving the transmitted portion of the laser light and converting at least a fraction of the transmitted portion of the laser light into a converted light having a second frequency different from the first frequency. An output port is optically coupled to the frequency converting optical element for outputting the converted light.Type: GrantFiled: May 22, 2006Date of Patent: June 10, 2008Inventor: Raman Kashyap
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Patent number: 7386018Abstract: A mode-locked laser serves as a light source for stabilizing the frequency of each optical carrier and generates high-quality optical multi-carrier. The mode-locked laser is equipped with a master laser for generating master laser light; a mode-locked laser section including in an optical resonator at least a modulating section, am amplifying section, and a bandwidth limiting section for reducing mode partition noise; and a signal generating section for generating a periodic signal that serves for mode locking of the mode-locked laser section and is to be applied to the modulating section. The master laser light is input to the optical resonator of the mode-locked laser section to cause injection locking. An optical multi-carrier source is constructed by combining this mode-locked laser with a waveguided optical nonlinear medium.Type: GrantFiled: February 3, 2005Date of Patent: June 10, 2008Assignee: Nippon Telegraph and Telephone CorporationInventors: Kunihiko Mori, Kenji Sato, Takuya Ohara
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Patent number: 7376162Abstract: In a method for stabilizing an optical output of a semiconductor laser: the semiconductor laser is heated with a heater when the semiconductor laser is not in operation; and the heating of the semiconductor laser is stopped, or the amount of heat supplied to the semiconductor laser is lowered, almost simultaneously with startup of the semiconductor laser.Type: GrantFiled: September 29, 2003Date of Patent: May 20, 2008Assignee: FUJIFILM CorporationInventors: Kazuhiko Nagano, Yoji Okazaki
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Patent number: 7372877Abstract: Fiber laser unit 1 comprises a plurality of fiber lasers 2 and 3 that generate laser beams by exciting a laser active substance inside cores 2a and 3a by exciting light, propagate the laser beams inside the cores 2a and 3a, and output the laser beams from the end portions 2c and 3c, wherein the respective fiber lasers 2 and 3 have resonators 4 and 5 that reflect the laser beams on both ends 2b, 2c, 3b, and 3c thereof and have a structure in which a part of the cores 2a and 3a is reduced in diameter, the diameter reduced portions of the cores 2a and 3a are made proximal to each other, injection synchronization is carried out inside the resonators 4 and 5 by laser beams leaked from the cores 2a and 3a, and a loss is applied to the port of either one of the fiber lasers 2 and 3.Type: GrantFiled: June 20, 2003Date of Patent: May 13, 2008Assignees: Hamamatsu Photonic K.K.Inventors: Akira Shirakawa, Kenichi Ueda, Hirofumi Kan, Hirofumi Miyajima
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Patent number: 7372878Abstract: A method and system decrease the amount of undesired laser radiation reaching a workpiece from a laser having a laser cavity and a Q-switch. The laser operates at any given time in one of at least two modes. In a first mode the laser emits pulses at a PRF (pulse repetition frequency) for selectively irradiating targets on or within a workpiece, and the pulses propagate along a propagation path to the workpiece. In a second mode less or no laser radiation desirably reaches the workpiece. The method is operable during the second mode. The method opens the Q switch more than the Q switch is open in the first mode, thereby limiting the amount of energy that builds up in the laser cavity and decreasing the peak energy of the laser radiation emitted in the second mode.Type: GrantFiled: August 31, 2004Date of Patent: May 13, 2008Assignee: Electro Scientific Industries, Inc.Inventors: Brady Nilsen, Steve Stone
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Patent number: 7369584Abstract: A method and apparatus are provided for controlling the operation of a Laser Projection Display (LPD). Generally, the LPD is comprised of a laser, an optical system and a controller. The laser is adapted to emit a beam of laser light. The optical system is adapted to scan the beam of laser light on a display surface in a two-dimensional raster pattern. The controller is adapted to control the rate at which the laser beam is scanned to produce regions of varying resolution on the display surface. The controller is also adapted to present laser light onto the display surface within only selected portions of the two-dimensional raster scan pattern so that spaced apart image regions may be created.Type: GrantFiled: June 30, 2004Date of Patent: May 6, 2008Assignee: Symbol Technologies, Inc.Inventors: Ron Goldman, Paul Dvorkis, Joseph Katz, Narayan Nambudiri, Miklos Stern, Chinh Tan, Carl Wittenberg, Frederick F. Wood, Dmitriy Yavid
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Patent number: 7369587Abstract: Optoelectronic devices and methods are used to maintain a CWDM transmitter operating within design parameters over an extended ambient temperature range. In order to avoid excessive wavelength drift with temperature shifts, lasers in the CWDM transmitters are heated or cooled to a selected temperature, for example by using a thermoelectric cooler. By heating and cooling the lasers, any wavelength drift that an ambient temperature variation might inflict on the laser is minimized to the range hotter or colder than the selected temperature. As the temperature range of the laser increases above the selected temperature, the AC swing driving the laser is increased to maintain a sufficient extinction ratio for acceptable transmitter performance.Type: GrantFiled: December 21, 2004Date of Patent: May 6, 2008Inventors: James Stewart, Anthony Ho
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Patent number: 7369742Abstract: The present invention provides a device and method to efficiently turn light from an optical fiber around a corner while avoiding the frustrated-TIR loss that would occur if the fiber were bent. The invention uses non-imaging optics which efficiently deal with beam divergence half-angles less than 90°. By recognizing that most light from a fiber optic source will have a divergence half-angle of less than 90 degrees, a practical solution is achieved using non-imaging optics.Type: GrantFiled: July 28, 2006Date of Patent: May 6, 2008Assignee: Nellcor Puritan Bennett Inc.Inventor: Michael E. Fein
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Patent number: 7369582Abstract: A high-power fiber laser amplifier with a laser wavelength of about 1060 to 1100 nm and an average laser power of more than about 500 W and an almost diffraction-limited beam quality (M2<1.5) comprises a double-clad laser fiber that has a separate, laser-active fiber core with an outer diameter of at least 20 ?m and a pump core that surrounds the fiber core and has an outer diameter of at least 50 ?m, and ytterbium-doped solid state laser that emits pump light with a wavelength of approximately 1030 nm, a beam quality of M2< of approximately 30 and a laser power of at least approximately 600 watts, for pumping the double-clad laser fiber.Type: GrantFiled: December 5, 2006Date of Patent: May 6, 2008Assignee: Trumpf Laser GmbH + Co. KGInventors: Maite Kumkar, Andreas Voss
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Patent number: 7369593Abstract: The semiconductor laser of the present invention includes a first conductivity-type cladding layer, a second conductivity-type cladding layer having at least one ridge structure extending in the direction of a resonator, an active layer disposed between the two cladding layers and a current blocking layer provided so as to cover at least a side face of the ridge structure. The current blocking layer includes a hydrogenated first dielectric film. In the structure having the current blocking layer formed of a dielectric, a light confining efficiency is enhanced, a threshold value of laser oscillation decreases, and current properties during the oscillation at a high temperature and with a high power are improved.Type: GrantFiled: August 17, 2004Date of Patent: May 6, 2008Assignee: Matsushita Electric Industrial Co., Ltd.Inventors: Kouji Makita, Hideto Adachi
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Patent number: 7366221Abstract: A laser apparatus is disclosed. The laser apparatus has a diffraction grating that receives laser light from a semiconductor laser, emits first order diffracted light having a predetermined wavelength to the semiconductor laser, and reflects zero-th order light, a reflection section that reflects the zero-th order light reflected by the diffraction grating, a hold section that holds the diffraction grating and the reflection section while an open angle of the diffraction grating and the reflection section is kept constant, the hold section being rotatable with a fulcrum of an intersection of an extended line of a front surface of the diffraction grating and an extended line of a front surface of the reflection section, and a linear drive section that rotates the hold section with a linear motion of a piezoelectric device that expands and shrinks by the piezoelectric effect.Type: GrantFiled: May 17, 2006Date of Patent: April 29, 2008Assignee: Sony CorporationInventors: Tomiji Tanaka, Hiroyuki Yamagata, Masaki Chiba
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Patent number: 7362783Abstract: A method of generating coherent radiation, wherein a first fundamental beam of radiation from a four level laser and a second fundamental beam of radiation from a three level laser are mixed in a non-linear body to obtain an output beam at the sum frequency of the two fundamental beams. The invention also relates to an arrangement for carrying out the method.Type: GrantFiled: June 13, 2002Date of Patent: April 22, 2008Assignee: Cobolt ABInventors: Stefan Spiekermann, Katrin Ekvall, Håkan Karlsson
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Patent number: 7359420Abstract: Arrays of vertical extended cavity surface emitting lasers (VECSELs) are disclosed. The functionality of two or more conventional optical components are combined into an optical unit to reduce the number of components that must be aligned during packaging. A dichroic beamsplitter selectively couples frequency doubled light out of the cavity. In one implementation the dichroic beamsplitter includes at least one prism.Type: GrantFiled: September 25, 2006Date of Patent: April 15, 2008Assignee: Arasor CorporationInventors: Andrei V. Shchegrov, Jason P. Watson, Dicky Lee, Arvydas Umbrasas, Rene Dato, John Green, Michael Jansen, Aram Mooradian
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Patent number: 7352790Abstract: A lasing apparatus includes a laser medium and a pump source. The laser medium includes one of a Holmium-doped fluoride crystal or a Holmium-doped fluorozirconate ZBLAN glass fiber. The pump source generates pulses that resonantly pump the laser medium such that the laser medium produces an output from the 5I5 level to the 5I7 level of Holmium. The pump source produces pulses having a duration that is at least as long as a storage time of the 5I5 level of the laser medium. The pump source pumps the laser medium with signals having a wavelength shorter than 1.67 ?m, with the laser medium producing an output having a wavelength of about 1.67 ?m.Type: GrantFiled: January 23, 2006Date of Patent: April 1, 2008Assignee: Northrop Grumman CorporationInventors: Anna M. Tabirian, Douglas P. Stanley, Steve Guch, Jr., Ronald R. Selleck, Lloyd H. Morton
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Patent number: 7352787Abstract: A vertical cavity surface emitting laser diode includes a lower semiconductor reflector, an active region, an upper semiconductor reflector constituting a resonator with the lower semiconductor reflector, a metallic part being formed on the upper semiconductor reflector, which has a first aperture defining an output region of laser light generated in the active region, and a light confining region being provided between the metallic part and the lower semiconductor reflector, and having a second aperture defining an emission region of the laser light. The upper semiconductor reflector includes a lenticular medium having a convex surface toward the lower semiconductor reflector.Type: GrantFiled: December 13, 2004Date of Patent: April 1, 2008Assignee: Fuji Xerox Co., Ltd.Inventors: Naotaka Mukoyama, Nobuaki Ueki
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Patent number: 7346086Abstract: The present invention provides an apparatus for monitoring a laser. The apparatus includes a plurality of sensors and a monitoring device capable of communicating with the plurality of sensors and configured to monitor an operating status of a laser. The plurality of sensors includes an optical power sensor, a first temperature sensor, and a power sensor and/or a current supply sensor. The present invention also provides a method for monitoring a laser. The method includes measuring an output optical power of the laser, measuring a temperature of the laser and/or a lasing medium exciting device, measuring an amount of current supplied to the exciting device and/or an amount of laser cavity excitation, and determining a current and/or predicted health status of the laser based on at least one of the optical power, the temperature of the laser, the temperature of the exciting device, the current and the driver power.Type: GrantFiled: November 23, 2004Date of Patent: March 18, 2008Assignee: Videojet Technologies, Inc.Inventors: Daniel J. Ryan, Tom Pienkowski
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Patent number: 7346090Abstract: A VCSEL with nearly planar intracavity contact. A bottom DBR mirror is formed on a substrate. A first conduction layer region is formed on the bottom DBR mirror. An active layer, including quantum wells, is on the first conduction layer region. A trench is formed into the active layer region. The trench is formed in a wagon wheel configuration with spokes providing mechanical support for the active layer region. The trench is etched approximately to the first conduction layer region. Proton implants are provided in the wagon wheel and configured to render the spokes of the wagon wheel insulating. A nearly planar electrical contact is formed as an intracavity contact for connecting the bottom of the active region to a power supply. The nearly planar electrical contact is formed in and about the trench.Type: GrantFiled: October 30, 2006Date of Patent: March 18, 2008Assignee: Finisar CorporationInventors: Ralph H. Johnson, R. Scott Penner, James Robert Biard
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Patent number: 7339963Abstract: A high speed optical channel including an optical driver and a photodetector in a CMOS photoreceiver. The optical channel driver includes a FET driver circuit driving a passive element (e.g., an integrated loop inductor) and a vertical cavity surface emitting laser (VCSEL) diode. The VCSEL diode is biased by a bias supply. The integrated loop inductor may be integrated in CMOS technology and on the same IC chip as either/both of the FET driver and the VCSEL diode. The photodetector is in a semiconductor (silicon) layer that may be on an insulator layer, i.e., SOI. One or more ultrathin metal electrodes (<2000 ?) on the silicon layer forms a Schottky barrier diode junction which in turn forms a quantum well containing a two dimensional electron gas between the ultrathin metal electrode and the Schottky barrier diode junction.Type: GrantFiled: November 27, 2002Date of Patent: March 4, 2008Assignee: International Business Machines CorporationInventors: Ferenc M. Bozso, Philip G. Emma
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Patent number: 7324569Abstract: A multi semiconductor source tunable spectroscopy system has two or more semiconductor sources for generating tunable optical signals that are tunable over different spectral bands. The system enables the combination of these tunable signals to form an output signal that is tunable over a combined band including these individual spectral bands of the separate semiconductor sources. The system further compensates for spectral roll-off associated with the semiconductor sources. Specifically, near the limits of the semiconductor sources' spectral bands, the power in the tunable signal tends to degrade or decrease. The system compensates for this roll-off using drive current control, attenuators, or electronic compensation.Type: GrantFiled: September 30, 2004Date of Patent: January 29, 2008Assignee: Axsun Technologies, Inc.Inventors: Dale C. Flanders, Walid A. Atia, Mark E. Kuznetsov
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Patent number: 7319709Abstract: A narrow linewidth fluorescent emitter can incorporate a chromophore into a microcavity that can support low-order optical modes.Type: GrantFiled: July 23, 2002Date of Patent: January 15, 2008Assignee: Massachusetts Institute of TechnologyInventors: Vikram C. Sundar, Moungi G. Bawendi, John D. Joannopoulos, Mihai Ibanescu