Patents Examined by Gioacchino Inzirillo
  • Patent number: 6570892
    Abstract: A passive mode-locked linear-resonator fiber laser using polarization-maintaining fibers and a saturable absorber to produce ultra short pulses and a long-term reliable operation with reduced maintenance. Such a fiber laser can be configured to produce tunable pulse repetition rate and tunable laser wavelength.
    Type: Grant
    Filed: April 16, 2002
    Date of Patent: May 27, 2003
    Assignee: Calmar Optcom, Inc.
    Inventors: Hong Lin, Katherine Y. Lin
  • Patent number: 6546027
    Abstract: The present invention is directed to a pulsed, mode-locked, picosecond laser having a solid-state laser medium, a saturable absorber (SA), and a passive negative feedback (PNF) element. The SA is “slow”, having an absorption recovery time which is longer than a desired duration of an output pulse. The SA and the PNF element together mode-lock the laser to produce an output pulse or pulses of the desired duration. Thus, according to the method of the invention, the solid-state laser medium is energized, whereupon the laser becomes mode-locked to produce the desired output pulses. The solid-state laser of the present invention is capable of producing very short, energetic output pulses, such as output pulses having a duration on the order of one or more picoseconds, and an energy of from about 100 &mgr;J to about 2 mJ. These output pulses are very stable. As the laser is of relatively simple construction, it is relatively easy to operate to produce this stable energy output.
    Type: Grant
    Filed: December 1, 1999
    Date of Patent: April 8, 2003
    Assignee: Hoya Photonics, Inc.
    Inventor: Dzhakhangir V. Khaydarov
  • Patent number: 6498802
    Abstract: An organic micro-cavity lasers which can reduce an optical loss and derive the lasing by the electrical pumping is disclosed. The laser of the present invention has a bottom mirror layer formed on a substrate, a bottom electrode formed on the bottom mirror layer, an active layer formed on the bottom electrode, a top electrode formed on a peripheral portion of the active layer and a top mirror layer formed on the active layer except the peripheral portion. Therefore, the laser of the present invention can greatly reduce the optical loss since it has the bottom mirror layer, the active layer and the top mirror layer. Also, the injection of current can sufficiently accomplished because the top electrode having a ring shape is formed at the peripheral portion of the active layer so as to inject the current to the active layer.
    Type: Grant
    Filed: December 30, 1999
    Date of Patent: December 24, 2002
    Assignee: Electronics and Telecommunications Research Institute
    Inventors: Hye-Yong Chu, Jeong-Ik Lee, Seong-Hyun Kim, Lee-Mi Do, Heuk Park, Do-Hoon Hwang, Tae-Hyoung Zyung
  • Patent number: 6438147
    Abstract: An external cavity laser system composed of a semiconductor diode laser (10), a temperature control (30) and injection current control (40) means the diode laser, an external cavity (60) with a wavelength selector and means for controlling the laser temperature (20), laser injection current and the wavelength selector (110) to obtain arbitrary frequencies within the tuning range of the laser.
    Type: Grant
    Filed: January 26, 1999
    Date of Patent: August 20, 2002
    Assignee: Perkin Elmer Instruments LLC
    Inventors: Chandra Roychoudhuri, David H. Tracy, William J. Hubbard
  • Patent number: 6438149
    Abstract: A method is provided for fabricating microelectromechanically tunable vertical-cavity surface-emitting lasers and microelectromechanically tunable Fabry-Perot filters with precise lateral and vertical dimensional control. Strained reflective dielectric film(s) are applied to a multiple quantum well structure to electronically band-gap-engineer the quantum wells. Appropriate strain in the reflective dielectric film layers is also used to create appropriate curvature in one of the reflective dielectric film stacks so as to form a confocal cavity between a planar reflective dielectric film layer and the curved reflective dielectric film layer in the vertical cavity surface emitting laser or filter. Laser and filter structures are also provided which include a suspended membrane structure made of a dielectric/metal membrane or metal film that supports a cavity-tuning reflective dielectric film stack while being anchored at the perimeter by metal support post(s).
    Type: Grant
    Filed: June 26, 1998
    Date of Patent: August 20, 2002
    Assignee: CoreTek, Inc.
    Inventors: Parviz Tayebati, Masud Azimi, Peidong Wang, Daryoosh Vakhshoori
  • Patent number: 6418156
    Abstract: An optically-pumped laser having a gain medium configured to provide a low loss, three-dimensional integrated optical pump cavity that substantially confines optical pump radiation within the lasing volume, which is particularly useful for efficiently pumping solid state gain media that has low pump dopant concentration. The integrated pump cavity includes a plurality of boundaries contiguous with the gain medium. An optical pump source such as a laser diode array supplies optical pump radiation that is input into the gain medium through one or more pump cavity windows with a propagation direction transverse to a laser axis defined through the gain medium. In some embodiments, an optical surface is situated opposite the window to approximately recollimate the input pump radiation. The optical pump cavity may be designed to concentrate the optical pump radiation and approximately uniformly pump the entire volume of the lasing medium.
    Type: Grant
    Filed: November 12, 1998
    Date of Patent: July 9, 2002
    Assignee: Raytheon Company
    Inventor: Eugene R. Peressini
  • Patent number: 6404797
    Abstract: In an apparatus and method for generating high power laser radiation, the geometry of the resonant laser cavity defines a fundamental spatial or transverse cavity mode. A gain medium is disposed within the resonant cavity and an energy source energizes the gain medium within a first volume. This causes spontaneous and stimulated energy emission to propagate in the gain medium in a direction transverse to the fundamental cavity mode. The transverse emission in turn optically pumps a second volume of the gain medium about the first volume. When the intensity of the transverse emission is sufficiently high, inversion and gain are produced in the second volume. By optimizing the geometry of the cavity such that the fundamental cavity mode is coupled to both the first and the second volumes encompassing the first pumped volume, the transversely-directed energy of the first volume which would otherwise be wasted is instead captured by the fundamental beam, improving the overall power efficiently of the laser.
    Type: Grant
    Filed: September 30, 1999
    Date of Patent: June 11, 2002
    Assignee: Novalux, Inc.
    Inventor: Aram Mooradian
  • Patent number: 6400739
    Abstract: A wavelength-stabilized laser configuration has a semiconductor laser and a wavelength regulating device. The regulating device contains an optical isolator, an optical filter, two detectors and a signal processing device. According to the invention, partial beams required for the detectors are coupled out by polarization filters that are contained in the optical isolator and are simultaneously used as beam splitters.
    Type: Grant
    Filed: June 22, 1999
    Date of Patent: June 4, 2002
    Assignee: Siemens Aktiengesellschaft
    Inventor: Franz Auracher
  • Patent number: 6400737
    Abstract: A closed-loop feedback control system with a temperature tuned, wavelength stabilized laser module. The system uses a feedback control signal dependent upon a predetermined gain to control the temperature of the laser module. The laser module has an output connected to a controller via filtering and reference circuitry. The controller inputs etalon and reference signals from the filtering and reference circuitry to monitor the optical amplitude and wavelength of the laser module output, as well as the temperature of the laser module. When the controller detects a change in a slope of the etalon signal, the controller calculates a new numeric gain based on the changed slope. The new numeric gain and temperature of the laser module is used to generate a new control signal to maintain the output of the laser module at a desired wavelength. By monitoring the slope of the etalon signals, the system is capable of performing automatic closed-loop gain adjustment.
    Type: Grant
    Filed: December 14, 1999
    Date of Patent: June 4, 2002
    Assignee: Agere Systems Guardian Corp.
    Inventors: Scott L. Broutin, John W. Stayt, Jr.
  • Patent number: 6389049
    Abstract: A discharge circuit for pulsed laser comprising a power source, main discharge electrodes for generating a laser beam, a main discharge capacitor charged with electrical charges for generating the main discharge between the main discharge electrodes, and a switching circuit for performing switching operations to charge the main discharge capacitor with electrical charges supplied from the power source in a prescribed repetition cycle, is provided, in parallel to the main discharge capacitors, with a circuit element for consuming or grounding the reverse current from the power source caused by overshoot generated directly after the main discharge, thereby attaining stable laser output without ill effects from overshoot voltage generated directly following discharge.
    Type: Grant
    Filed: October 5, 1998
    Date of Patent: May 14, 2002
    Assignees: Komatsu Ltd., Kabushiki Kaisha Meidensha
    Inventors: Daisuke Yoshida, Toshihiro Nishisaka, Yuichi Takabayashi, Takashi Matsunaga, Hisashi Yanase, Tadao Shibuya, Yasuo Kataoka, Masayuki Tani, Eiji Sasamoto, Hiroyuki Hiyoshi, Kiyoshi Hara
  • Patent number: 6385218
    Abstract: On a “schedule” screen appearing on a display the user performs desired set value entries or action instructions on the apparatus by means of key entries. In order to set and enter a reference waveform for waveform control in particular, desired numerical value data are set and entered into items of a laser output reference value PEAK and waveform elements ↑ SLOPE, FLASH1, FLASH2, FLASH3 and ↓ SLOPE. Within the interior of the apparatus the reference waveform for waveform control and a reference waveform graph for display are obtained on the basis of the entered set values of the waveform element items. The reference waveform for waveform control is used as a reference value for the waveform control in the laser output waveform control. The reference waveform graph for display appears in a predetermined area on the screen in response to a predetermined key action.
    Type: Grant
    Filed: February 19, 1999
    Date of Patent: May 7, 2002
    Assignee: Miyachi Technos Corporation
    Inventors: Haruki Sasaki, Kouji Kawamura
  • Patent number: 6385229
    Abstract: A laser beam having a high power and preferable quality is obtained by a laser using a laser medium having a wide active region or a large mode volume. The laser includes a laser source, first and second resonator mirrors as a laser resonator optical system, an array illuminator optical system which is placed within the resonator optical system and places, at even spacing in a plane perpendicular to an optical axis of the resonator, complex amplitude distributions including only a fundamental transverse mode in a uniform phase similar to a fundamental transverse mode component of a laser beam emitted from the laser beam source. A higher-order mode component is diffracted in an angle larger than its diffraction angle and eliminated outside the resonator.
    Type: Grant
    Filed: December 8, 1998
    Date of Patent: May 7, 2002
    Assignee: Fuji Photo Film Co., Ltd.
    Inventor: Hiroyuki Hiiro
  • Patent number: 6377351
    Abstract: A fiber-optic laser gyroscope having phase sensitive detecting means which can reduce rotation rate measurement errors. In the fiber-optic laser gyroscope, errors due to the relative intensity difference between two consecutive pulses, which was an error factor in rotation rate measurement through time interval measurement between two adjacent pulses, can be eliminated by having a phase sensitive detection means which may extract and detect only components having the same phase as that of a phase-modulated signal from components having the same frequency as that of a phase-modulated signal. An output from the phase sensitive detecting means has an additional characteristic of being linearly proportional to rotation rate. The fiber-optic laser gyroscope of the present invention, therefore, has a characteristic of a relatively simple signal processing compared to conventional interferometric fiber gyroscopes.
    Type: Grant
    Filed: November 4, 1999
    Date of Patent: April 23, 2002
    Assignee: Korea Advanced Institute of Science and Technology
    Inventors: Byoung Yoon Kim, Jong Bum Hong, Young Bae Yeo, Bong Wan Lee
  • Patent number: 6377597
    Abstract: A gallium nitride semiconductor laser device has an active layer (6) made of a nitride semiconductor containing at least indium and gallium between an n-type cladding layer (5) and a p-type cladding layer (9). The active layer (6) is composed of two quantum well layers (14) and a barrier layer (15) interposed between the quantum well layers, and constitutes an oscillating section of the semiconductor laser device. The quantum well layers (14) and the barrier layer (15) have thicknesses of, preferably, 10 nm or less. In this semiconductor laser device, electrons and holes can be uniformly distributed in the two quantum well layers (14). In addition, electrons and holes are effectively injected into the quantum well layers from which electrons and holes have already been disappeared by recombination. Consequently, the semiconductor laser device has an excellent laser oscillation characteristic.
    Type: Grant
    Filed: September 2, 1999
    Date of Patent: April 23, 2002
    Assignee: Sharp Kabushiki Kaisha
    Inventor: Toshiyuki Okumura
  • Patent number: 6377591
    Abstract: The modularized fiber optic laser system includes at least one master oscillator for producing a master laser signal and a plurality of optical amplification modules that independently amplify portions of the master laser signal. Each optical amplification module includes a plurality of optical fiber amplifiers and at least one pump source associated with each optical fiber amplifier for pumping the respective optical fiber amplifier. The optical amplification module also includes a power source for providing power to the pump sources. Each optical amplification module preferably consumes no more than a first predetermined amount of power during operation. As such, the power source is adapted to provide at least a first predetermined amount of power without recharging and without power generation. Each optical amplification module is also designed to produce no more than a first predetermined amount of heat during operation.
    Type: Grant
    Filed: December 9, 1998
    Date of Patent: April 23, 2002
    Assignee: McDonnell Douglas Corporation
    Inventors: Jack Herbert Hollister, Mark Steven Zediker
  • Patent number: 6377599
    Abstract: An optical device has a mount including a mount surface with a longitudinal axis. A diode source has a first diode emitter producing a first beam, a second diode emitter producing a second beam and a third diode emitter producing a third beam. The diode source is mounted above the mount surface at an angle &thgr; relative to the longitudinal axis of the mount. A prism array has a first prism face, a second prism face and a third prism face. The prism array has an angled surface cut at the angle &thgr; relative to a longitudinal axis of the prism array. The first, second and third beams are incident on the first, second and third prism faces respectively. Optical path lengths between the first, second and third diode emitters relative to the first, second and third prism faces are equal.
    Type: Grant
    Filed: January 12, 1999
    Date of Patent: April 23, 2002
    Assignee: Iridex Corporation
    Inventor: Larry R. Marshall
  • Patent number: 6373563
    Abstract: An optical source generates optical signals as a result of varying polarization states to achieve oscillation within an optical loop. The optical signals have narrow spectral width and the optical source is tuneable, so that optical components stimulated by the optical signals can be characterized over a predefined wavelength range with high wavelength resolution. The optical loop includes an optical gain element, a tuneable filter, and a polarization scrambler that provides a varying polarization transfer function. The optical gain element has sufficiently high gain within the passband of the tuneable filter and the polarization transfer function is sufficiently varied to attain oscillation within the optical loop, thereby generating the optical signals. The varying polarization transfer function of the polarization scrambler produces a corresponding variation in the polarization of the generated optical signals, which are coupled from the optical loop to an output.
    Type: Grant
    Filed: November 12, 1999
    Date of Patent: April 16, 2002
    Assignee: Agilent Technologies, Inc.
    Inventors: James R. Stimple, Kenneth R. Wildnauer
  • Patent number: 6373867
    Abstract: A passive mode-locked linear-resonator fiber laser using polarization-maintaining fibers and a saturable absorber to produce ultra short pulses and a long-term reliable operation with reduced maintenance. Such a fiber laser can be configured to produce tunable pulse repetition rate and tunable laser wavelength.
    Type: Grant
    Filed: June 21, 2000
    Date of Patent: April 16, 2002
    Assignee: Calmar Optcom, Inc.
    Inventors: Hong Lin, Katherine Y. Lin
  • Patent number: 6373874
    Abstract: An n-type GaAs buffer layer 702, an n-type AlGaInP cladding layer 703, a multiple quantum well active layer 704 made of AlGaInP and GaInP, a first p-type AlGaInP cladding layer 705a, an optical guide layer 707, a second p-type cladding layer 705b, a p-type GaInP saturable absorption layer 706, and a third p-type AlGaInP cladding layer 707 are sequentially formed on an n-type GaAs substrate 701. In this structure, the volume of the saturable absorption layer is reduced, and the optical guide layer is provided. As the volume of the saturable absorption layer becomes smaller, the more easily the carrier density can be increased, the more easily the saturated state can be attained, and the more remarkable the saturable absorption effect becomes. Thus, a semiconductor laser having stable self-oscillation characteristics and, as a result, having a low relative noise intensity is realized.
    Type: Grant
    Filed: August 14, 1998
    Date of Patent: April 16, 2002
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Isao Kidoguchi, Hideto Adachi, Masaya Mannoh, Toshiya Fukuhisa, Akira Takamori
  • Patent number: 6367624
    Abstract: Disclosed is an optical component packaging assembly including a rectangular plastic box with an upper half and a lower half. In the lower half, a thermal plastic vacuum formed insert is positioned within the lower half. The lower insert has a recess. The recess has opposed convex ends and central finger recesses. The opposed convex ends prevent the end faces of the optical component from being brought into contact with the insert. The convex ends may be v-shaped or semi-circular. The finger recesses provide convenient access to the laser rod so that the person unpackaging the laser rod from the optical component packaging is most likely to engage the laser rod at a center portion thereof rather than grasping the laser rod at the end faces thereof, thereby inadvertently damaging the optical surfaces of the laser rod.
    Type: Grant
    Filed: October 14, 1998
    Date of Patent: April 9, 2002
    Assignee: Northrop Grumman Corporation
    Inventors: Paul W. Szczepanski, David J. Monks