Patents Examined by James W. Davie
  • Patent number: 6366595
    Abstract: A kink suppression technique is disclosed in which optical characteristics of a distributed feedback laser diode's resonant cavity are controlled to preferentially prevent establishment of higher order lateral modes. This results in increased kink powers and thus the useful power range of the device. Specifically, an optical layer, preferably silicon or titanium, is disposed along the optical axis, on the etched upper cladding layer, and on both sides of the ridge.
    Type: Grant
    Filed: June 20, 2000
    Date of Patent: April 2, 2002
    Assignee: Corning Lasertron, Inc.
    Inventor: Dennis P. Bowler
  • Patent number: 6366593
    Abstract: A precision positioning mount for UV-cured adhesives that provides adhesive junctions between modular assembly mounts and structural elements. Contact edges are placed on a first fixating area of an adhesive junction. The contact edges are pronounced edges of faces that slide along a second fixating area during the adjustment process. Thus, the assembly modules and structural elements are precisely referenced before, during and after their positioning and orientating. First and second fixating areas form a cavity that provides a volume for the adhesive. The mounts and structural elements are preferably made of sapphire for increased thermal conductivity. The elements of the assembly mounts are modular and interchangeable and provide various positioning modes.
    Type: Grant
    Filed: December 1, 1999
    Date of Patent: April 2, 2002
    Assignee: Lightwave Electronics Corporation
    Inventors: Derek J. Richard, Mark Byer, Gerald Mitchell, George Conway
  • Patent number: 6366597
    Abstract: A monolithic long-wavelength vertical optical cavity device built up along a vertical direction. The device, when designed as a surface emitting laser, has a bottom Distributed Bragg Reflector (DBR), an active region consisting of active bulk medium or quantum wells, a current confinement layer next to the active layer, and a top DBR. The bottom DBR and the active region are lattice matched to the lattice defining material, while the top DBR is lattice relaxed. The design achieves high reflectivity, low absorption and diffraction loss. The design also ensures low production cost due to low precision requirement and wafer size production. The device can be used as a light detector when the active region is replaced by a spacer or a optical filter.
    Type: Grant
    Filed: August 16, 1999
    Date of Patent: April 2, 2002
    Assignee: Bandwidth9 Inc.
    Inventors: Wupen Yuen, Gabriel S. Li, Contance J. Chang-Hasnain
  • Patent number: 6363090
    Abstract: A laser system for the generation of an ultra-short light pulse—with a laser resonator which contains at least one active solid-state oscillator element, preferably a thin disk of a laser-active crystal with a high amplification bandwidth, particularly of a “quasi-three-level” system such as Yb:YAG—comprises at least one respective arrangement for phasecoupling of the laser modes and for dispersion compensation. For industrial applications,in order to be able to emit ultra-short pulses with very high average powers in a power-scalable fashion while being constructed optimally simply and inexpensively, the arrangement for phase coupling is constructed as a passive, non-linear element, and a prismless arrangement for dispersion compensation is provided.
    Type: Grant
    Filed: February 24, 1999
    Date of Patent: March 26, 2002
    Assignee: Dentek-Lasersystems Produktions Ges.m.b.H
    Inventors: Ernst Wintner, Evgeni Sorokin, Irina Sorokina
  • Patent number: 6363096
    Abstract: A laser structure may be used to fabricate a plastic laser and achieve electrically-driven lasing action. The structure comprises an LED, a waveguide laser, and a substrate disposed between them. The substrate has a first and a second side. Light emitted from the LED is received by the substrate at the first side and concentrated as it is guided with the body of the substrate to the second side, where it is received by the laser. Concentration of the light across the substrate improves the efficiency of the device and leads to lower threshold powers.
    Type: Grant
    Filed: August 30, 1999
    Date of Patent: March 26, 2002
    Assignee: Lucent Technologies Inc.
    Inventors: Ananth Dodabalapur, Attila Mekis, John A. Rogers, Richart Elliott Slusher
  • Patent number: 6363095
    Abstract: A laser system for operation at elevated temperatures with minimal cooling requirements. The laser system comprises a laser media having first and second optical ends and an input port. The laser system further comprises at least one high-temperature laser diode which optically communicates with the laser media and is operative to generate a source beam of light which is transmitted into the input port of the laser media. Optically communicating with the first optical end of the laser media is at least one reflector, while optically communicating with the second optical end of the laser media is at least one optical coupler. The laser media, the reflector and the optical coupler are configured to form a laser resonator operative to generate a laser beam which is transmitted through the optical coupler.
    Type: Grant
    Filed: May 6, 1999
    Date of Patent: March 26, 2002
    Assignee: Northrop Grumman Corporation
    Inventors: Ronald B. Jones, Michael A. Guy, Gerald P. Griffith, Ralph L. Burnham, Ti Chuang
  • Patent number: 6363097
    Abstract: A semiconductor laser with a rewritable wavelength stabilizer which comprises a laser mirror made of a grating written into a photorefractive material, in which the oscillation wavelength of the laser diode is determined by the period of the grating. This allows the refractive index of the grating to be changed by illuminating the photorefractive material after cooling thereof to a temperature at which most of the doped impurities form DX centers. The grating can be erased by heating the photorefractive material to a temperature at which most DX centers are ionized, which erases the grating. Thereafter the photorefractive material is cooled again to a temperature at which most impurities become DX centers, and a new grating can be written in the photorefractive material. The wavelength of the semiconductor laser can be changed repeatedly by erasing and rewriting the grating therein.
    Type: Grant
    Filed: September 18, 1998
    Date of Patent: March 26, 2002
    Assignee: NEC Corporation
    Inventors: Richard A. Linke, Hirohito Yamada
  • Patent number: 6359914
    Abstract: A tunable pulsed narrow bandwidth light source and a method of operating a light source are provided. The light source includes a pump laser, first and second non-linear optical crystals, a tunable filter, and light pulse directing optics.
    Type: Grant
    Filed: October 4, 1999
    Date of Patent: March 19, 2002
    Assignee: University of Dayton
    Inventors: Peter E. Powers, Thomas J. Kulp
  • Patent number: 6359919
    Abstract: A gallium nitride-based compound semiconductor laser has a double-heterojunction structure, in which an active layer is sandwiched between cladding layers, on a sapphire substrate. A GaN current blocking layer having a striped opening portion is formed on the p-cladding layer. A p-GaN buried layer and a contact layer through which a current is injected into the opening portion of the current blocking layer and which are larger in area than the opening portion are formed. The active layer has a multiple quantum well structure constituted by a cyclic structure formed by cyclically stacking two types of InGaAlN layers which have different band gaps and are 10 nm or less thick.
    Type: Grant
    Filed: August 22, 2000
    Date of Patent: March 19, 2002
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Masayuki Ishikawa, Masahiro Yamamoto, Shinya Nunoue, Johji Nishio, Genichi Hatakoshi, Hidetoshi Fujimoto
  • Patent number: 6359921
    Abstract: In a semiconductor laser element including a multilayered structure being formed of a plurality of semiconductor layers made of a plurality of group III-V compounds, and having at least a pair of cleaved end surfaces as a pair of light resonator surfaces, a first reflectance control layer, made of an oxygen gettering material which has a function of gettering oxygen, is formed on at least one of the pair of light resonator surfaces, and a second reflectance control layer made of a nitride of a group III material is formed on the first reflectance control layer.
    Type: Grant
    Filed: August 30, 2000
    Date of Patent: March 19, 2002
    Assignee: Fuji Photo Film Co., Ltd.
    Inventor: Fusao Yamanaka
  • Patent number: 6359920
    Abstract: Several methods are used in novel ways with newly identified and viable parameters to decrease the peak transition energies of the pseudomorphic InGaAs/GaAs heterostructures. These techniques, taken separately or in combination, suffice to permit operation of light emitting devices at wavelengths of 1.3 &mgr;m or greater of light-emitting electro-optic devices. These methods or techniques, by example, include: (1) utilizing new superlattice structures having high In concentrations in the active region, (2) utilizing strain compensation to increase the usable layer thickness for quantum wells with appropriately high In concentrations, (3) utilizing appropriately small amounts of nitrogen (N) in the pseudomorphic InGaAsN/GaAs laser structure, and (4) use of nominal (111) oriented substrates to increase the usable layer thickness for quantum wells with appropriately high In concentrations.
    Type: Grant
    Filed: May 26, 1999
    Date of Patent: March 19, 2002
    Assignee: Picolight Incorporated
    Inventors: Jack L. Jewell, Henryk Temkin
  • Patent number: 6359918
    Abstract: A light source controller having a look-up table that indicates the amount of current to be provided to a light source to maintain wavelength and spectrum stability at various temperatures. Further, the light source may have a heater/cooler to maintain a constant temperature of the light source. The controller provides the appropriate current to the light source from the time of turn-on until it achieves thermal equilibrium, to provide an output having a relatively constant wavelength during the warm-up period and during changes of ambient temperature about the light source. The light source may have a heater and/or cooler to maintain a constant ambient temperature, so that the light source controller can provide a more refined control of the light source output wavelength and spectrum. The light source controller may be particularly used for a light source in a fiber optic gyroscope.
    Type: Grant
    Filed: June 30, 1998
    Date of Patent: March 19, 2002
    Assignee: Honeywell International Inc.
    Inventor: Michael S. Bielas
  • Patent number: 6356574
    Abstract: A multistage optical amplifier pumping system with built-in redundant reliability for lightwave communication system provides plural levels of redundancy. A first level of redundancy deals with redundancy in the form of plural primary laser diode sources for pumping a single fiber laser pump source. A second level of redundancy deals with redundancy of a plurality of fiber laser pump sources for pumping a plurality of serially connected injection signal fiber amplifiers forming the multistage amplifier system. If one of fiber pump sources should fail, increased pumping power is available from the remaining fiber pump sources via their respectively connected amplifier stages. A third level of redundancy deals with redundancy in the employment of multiple single mode laser emitters on the same chip or bar sufficiently segmented and/or electrical isolated so as not to interfere with operation of or cause failure to adjacent or neighboring emitters on the same chip or bar.
    Type: Grant
    Filed: January 29, 1999
    Date of Patent: March 12, 2002
    Assignee: SDL, Inc.
    Inventors: Richard R. Craig, Robert L G. Waarts, David F. Welch, John G. Endriz, Dirk J. Kuizenga, Steven Sanders
  • Patent number: 6356572
    Abstract: It is an object of the present invention to provide a semiconductor light emitting device capable of securing, in use of an optical information processing or an optical communication system, a low threshold and high efficiency operation as well as a high output characteristic. An active layer structure having a flatness and an interface acuteness of a quantum well structure improved by introducing a multi-period super lattice structure between a substrate for crystal growth and a light emitting layer area further to on a misoriented substrate sued to enhance a homogeneity of a semiconductor crystal. Further, a carrier confinement and a light confinement can be enhanced by providing a margin for design of the quantum well structure.
    Type: Grant
    Filed: March 16, 1999
    Date of Patent: March 12, 2002
    Assignee: Hitachi, Ltd.
    Inventors: Toshiaki Tanaka, Kenji Hiruma, Hiroshi Hamada
  • Patent number: 6356573
    Abstract: A top surface emitting vertical cavity laser with enhanced power handling capacity. The laser provides a patterned top electrode for uniformly injecting applied current to the active area. The diameter of the electrode relative to the vertical distance between it and the active layer is reduced by patterning. The result is an improved laser with significant power output.
    Type: Grant
    Filed: January 22, 1999
    Date of Patent: March 12, 2002
    Assignee: Mitel Semiconductor AB
    Inventors: Jan Jonsson, Vilhelm Oscarsson
  • Patent number: 6356570
    Abstract: A source of intense coherent high-frequency electromagnetic radiation such as soft x-rays. A circularly polarized incident beam of coherent radiation is directed at a frequency multiplication medium that includes constituents of approximate Cn symmetry, oriented so that the symmetry axes of the constituents are parallel to the incident beam. The interaction of the incident beam and the constituents of the medium produces higher harmonics of the incident frequency, up into the x-ray band. If the Cn symmetry of the medium constituents is exact then the harmonic frequencies are multiples ln±l of the frequency of the incident beam, where l is an integer. If the Cn symmetry is only approximate, then the harmonics are centered around these multiples. Suitable medium constituents include dipolar molecules of C5v symmetry and circular rings of nanoparticles.
    Type: Grant
    Filed: August 11, 2000
    Date of Patent: March 12, 2002
    Assignee: Technion Research and Development Foundation LTD
    Inventors: Ofir Alon, Vitali Averbukh, Nimrod Moiseyev
  • Patent number: 6353623
    Abstract: Apparatus and methods for monitoring the wavelength of laser radiation and that provide a temperature-corrected error signal responsive to the deviation of the wavelength of the laser radiation from a nominal wavelength is disclosed. The apparatus includes a least one optical filter for filtering the laser radiation according to at least one spectral filter function to produce filtered laser radiation and at least one optical detector for detecting the filtered laser radiation to produce a first detected signal. The apparatus also includes a temperature sensor for sensing temperature characteristic of at least the optical filter and processing circuitry for providing a temperature-corrected output signal responsive to the deviation of the wavelength of the laser radiation from the nominal wavelength.
    Type: Grant
    Filed: January 4, 1999
    Date of Patent: March 5, 2002
    Assignee: Uniphase Telecommunications Products, Inc.
    Inventors: Timothy C. Munks, Paul E. Dunn, David J. Allie
  • Patent number: 6353625
    Abstract: An array type laser diode includes an active layer, a cathode electrode, and bonding electrodes. The active layer is formed in a substrate into a stripe shape to serve as an emission portion. The cathode electrode is formed on a mounting surface of the substrate into a stripe shape to be close to the active layer. The bonding electrodes are formed on the mounting surface of the substrate to be physically separated from the drive electrode.
    Type: Grant
    Filed: February 9, 1999
    Date of Patent: March 5, 2002
    Assignee: NEC Corporation
    Inventor: Isao Yoneda
  • Patent number: 6353624
    Abstract: Semiconductor laser with a tunable gain spectrum. Said laser comprises an active zone having at least one active quantum well (AQW), which emits a laser radiation during the introduction of carriers into the active zone and at least one collection quantum well (CQW1, CQW2) on either side of the active well, for collecting and confining part of the carriers introduced. Means for distributing carriers in the collection wells are provided for creating a space charge field for modifying, during the emission of radiation and by an electrooptical effect, the gain spectrum of said active well. Application to optical telecommunications.
    Type: Grant
    Filed: September 16, 1999
    Date of Patent: March 5, 2002
    Assignee: Commissariat a l'Energie Atomique
    Inventors: Nikolaos Pelekanos, Valentin Ortiz, Guido Mula
  • Patent number: 6351481
    Abstract: The screening of edge-emitting laser diode bars in a production line is permitted by fabricating the source electrodes of each diode in the bar in two parts spaced apart to form a window aligned with the lasing cavity of the diode. Such windows have been made in failed devices to determine the cause of failure. Here, the windows are formed in a wafer stage of fabrication for later separation into laser bars or individual laser diodes. All wafers, all laser bars and all laser diodes are fabricated with windows thus permitting automatic screening during fabrication rather than opening a window to examine only failed devices as is the case in the prior art.
    Type: Grant
    Filed: October 6, 1999
    Date of Patent: February 26, 2002
    Assignee: Opto Power Corp
    Inventors: Steve Marcomber, Rushikesh Patel, Sheng-Hui Yang