Patents Examined by Ellen E. Kang
  • Patent number: 5995527
    Abstract: A semiconductor laser device including Ga.sub.x Al.sub.y In.sub.1-x-y N (0.ltoreq.x.ltoreq.1, 0.ltoreq.y.ltoreq.1)) layers has an InN contact layer, which has a thickness ranging, preferably, from 0.1 .mu.m to 1.0 .mu.m inclusive. The contact layer is formed by a MOCVD method. When materials for formation of the InN contact layer are fed into a reactor, an organic radical material is also fed and a substrate temperature is controlled to be about 800.degree. C. during the process of growth of the InN layer.
    Type: Grant
    Filed: February 20, 1997
    Date of Patent: November 30, 1999
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Yoshihiro Ueta, Kazuhiko Inoguchi, Takayuki Yuasa
  • Patent number: 5995528
    Abstract: A semiconductor laser includes a first clad layer, a first optical waveguide layer, a first barrier layer, an active layer, a second barrier layer, a second optical waveguide layer and a second clad layer formed in this order on a GaAs substrate which is a III-V group compound semiconductor. Each of the layers contains As and P, each of the first and second clad layers and the first and second optical waveguide layers is of a composition which matches with the GaAs substrate in lattice. The active layer is of a composition which induces compression strain on the GaAs substrate, and each of the first and second barrier layers is of a composition which induces tensile strain on the GaAs substrate, thereby compensating for the compression strain induced in the active layer.
    Type: Grant
    Filed: March 28, 1997
    Date of Patent: November 30, 1999
    Assignee: Fuji Photo Film Co., Ltd.
    Inventors: Toshiaki Fukunaga, Mitsugu Wada
  • Patent number: 5991481
    Abstract: An optical isolator, which has: a medium through which a light transmits and in which a dynamic diffraction grating that periodically repeats a refractive index distribution is formed; wherein the dynamic diffraction grating causes a propagation loss difference between an incident light which is supplied into the medium and a returning light which is supplied into the medium in a direction reverse to the incident light.
    Type: Grant
    Filed: April 28, 1997
    Date of Patent: November 23, 1999
    Assignee: NEC Corporation
    Inventor: Yidong Nuang
  • Patent number: 5991322
    Abstract: A semiconductor optical device includes a first semiconductor layer, and a diffraction grating disposed on the first semiconductor layer. The diffraction grating includes portions of a superlattice layer grown on the first semiconductor layer and including alternatingly arranged second semiconductor layers of a semiconductor material in which mass transport hardly occurs during growth of other semiconductor layers and third semiconductor layers of a semiconductor material different from the material of the second semiconductor layers. The device includes a fourth semiconductor layer burying the diffraction grating. In this structure, since the second semiconductor layers are included in the diffraction grating, the shape of the diffraction grating is maintained during the vapor phase deposition of the fourth semiconductor layer. Therefore, the thickness, amplitude, and pitch of the diffraction grating that determine the optical coupling constant are controlled with high precision.
    Type: Grant
    Filed: July 21, 1995
    Date of Patent: November 23, 1999
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Tohru Takiguchi, Katsuhiko Goto, Hirotaka Kizuki
  • Patent number: 5987203
    Abstract: A distribution module for use in a traditional electrical panel that provides coupling functionality for optical and electrical connectors. The distribution module is comprised of a housing with a passage defined therein. The distribution module further includes high density, modular coupling strips, which are chosen based on the type of connectors to be coupled. These coupling strips are joined together and then secured in the passage formed in the housing. Once assembled, the distribution module is received into an opening in the panel thereby integrating both optical and electrical couplers in a single panel.
    Type: Grant
    Filed: October 9, 1997
    Date of Patent: November 16, 1999
    Assignee: Lucent Technologies Inc.
    Inventors: John N. Abel, Paul F. Kolesar, Richard M. Flynn, Daniel L. Stephenson
  • Patent number: 5984534
    Abstract: Replicated polymeric microstructures have been used in the fabrication of optofiber waveguide connections, with the intention of simplifying the production of such connections, and therewith greatly reduce manufacturing costs. Fabrication is commenced from a silicon chip in which there has been etched grooves whose cross-sectional shape has been adapted to accommodate waveguides, such as optofibers. Firstly, the silicon chip is replicated, by plating the silicon chip with nickel for instance. The replication then serves as a model for producing a plastic copy of the silicon chip. This method of manufacture is able to produce waveguide accommodating grooves (2), such as optofiber accommodating grooves, to a very high degree of accuracy. Furthermore, the method provides a high degree of freedom in the configuration of the grooves, and also enables branched grooves for receiving branched fibres to be produced.
    Type: Grant
    Filed: March 24, 1997
    Date of Patent: November 16, 1999
    Assignee: Telefonaktiebolaget LM Ericsson
    Inventors: H.ang.kan Elderstig, Olle Larsson, Goran Palmskog, Ove Ohman
  • Patent number: 5984530
    Abstract: An improved optical fiber connector design and associated manufacturing method which provides increased manufacturing throughput by molding connector bodies as a unitary molded part as joined back-to-back pairs of connector bodies.
    Type: Grant
    Filed: September 24, 1997
    Date of Patent: November 16, 1999
    Assignee: Lucent Technologies, Inc.
    Inventor: Muhammed A. Shahid
  • Patent number: 5987206
    Abstract: A method and apparatus for separating optical fibers contained in a multiple-fiber cable is disclosed. The method has particular application for separating long cables, that is, of about ten centimeters or more, of the type having a king wire and a plurality of fibers concentrically arranged around the king wire and embedded in a matrix material. The method involves stringing the cable in a taut position and moving a separation mold between the fibers and along the length of the cable while applying heat to the cable.
    Type: Grant
    Filed: August 28, 1997
    Date of Patent: November 16, 1999
    Assignee: Lucent Technologies Inc.
    Inventor: Rocco Romeo
  • Patent number: 5982964
    Abstract: A method of fabricating an optical device incorporates two different techniques for formation of different structures of the device on the same substrate. Individual processes such as Titanium indiffusion and annealed proton exchange in LiNbO.sub.3 require significantly different temperature ranges for comparable waveguide formation. The present method combines these processes and allows for temperature tuning of the optical parameters of passive and active components, for instance coupling lengths of directional couplers, associated with one section of the device without altering the optical parameters of similar components in the other sections. The process improves yield for devices which employ more than one precisely fabricated optical directional coupler by creating an extra degree of process freedom.
    Type: Grant
    Filed: June 30, 1997
    Date of Patent: November 9, 1999
    Assignee: Uniphase Corporation
    Inventors: Jeffrey M. Marx, Robert W. Ade, Jack Lin
  • Patent number: 5980118
    Abstract: A connector for connecting one end of an opto fibre to an optical component includes a retaining sleeve for a portion of the fibre near said end of the optical fibre, and a structure carrying the retaining sleeve and intended to be fixed with respect to the optical component. A spring acts between the retaining sleeve and the carrying structure for compensating for tolerances in the length direction of the retaining sleeve at connection to the optical component. The spring and the carrying structure are mutually shaped to admit introduction of the retaining sleeve together with the fibre held thereby, into the carrying structure prior to the spring sidewardly into the carrying structure.
    Type: Grant
    Filed: February 20, 1998
    Date of Patent: November 9, 1999
    Assignee: Telefonaktiebolaget LM Ericsson
    Inventors: Uno Henningsson, Michael Lynn
  • Patent number: 5978532
    Abstract: A spectrographic type multiplexer and/or demultiplexer optical component having an array of waveguides, the component comprising a star inlet coupler and a star outlet coupler with said array extending therebetween, and also comprising an inlet light guide and an outlet light guide for said inlet and outlet couplers, respectively, wherein the spectrum response of the component is the sum of two substantially Gaussian spectrum responses of peaks that are offset in wavelength.
    Type: Grant
    Filed: September 22, 1997
    Date of Patent: November 2, 1999
    Assignee: France Telecom
    Inventors: Arnaud Rigny, Catherine Ramus, Adrien Bruno
  • Patent number: 5978528
    Abstract: A method and various structures are described for reducing excess photon noise in short coherence light sources, such as broadband superfluorescent fiber or superluminescent diodes, for example. The method contemplates splitting the light source signal into a plurality of components, thereby splitting, and reducing, the photon noise or "beat noise" as well as the light intensity. Each component travels in a separate path having a unique time delay which is longer than the coherence time of the light source. The light from each separate path is recombined at an output end, prior to detection, causing the signal to get back to its original intensity, while keeping the total beat noise at a reduced level. The paths may be created using different length polarization maintaining (PM) fibers, different length optical fibers, or multi-mode fibers having several propagation modes propagating at different rates.
    Type: Grant
    Filed: April 2, 1997
    Date of Patent: November 2, 1999
    Assignee: Litton Systems, Inc.
    Inventor: Bernard G. Fidric
  • Patent number: 5978527
    Abstract: A thermal optical switching cell has a channel of either gas or boilable liquid that crosses an optical waveguide at a forty-five degree angle. Two or more appropriately placed heaters use the water/steam/dry states of thermal ink jet technology to quickly insert, or extract, boilable liquid respectively into, or from, the channel. The boilable liquid has an index of refraction close to that of the guide. In the wet state, the channel contains the liquid and nearly all the light of the incoming guide traverses the liquid along the axis of the guide. In the dry state, the channel contains gas. Total internal reflection (TIR) occurs and light is directed at right angles away from the axis of the incoming channel. Adding a second waveguide, perpendicular to, and intersecting the first waveguide at the channel, forms a cross-bar switch. These liquid switching cells toggle between the wet and dry states. No power is required to hold the switch in the most recent state.
    Type: Grant
    Filed: August 3, 1998
    Date of Patent: November 2, 1999
    Assignee: Hewlett-Packard Company
    Inventor: David K. Donald
  • Patent number: 5966482
    Abstract: An optical near-field probe (1) includes a carrier component (10), which carries a tip (40), and has only one membrane (11, 20), transparent at least in the area of the tip (40), which is mounted on the light emission surface (9) of an optical waveguide (2) that is made of a rigid material such as glass or plastic. The dimensions of the membrane (11, 20), at least in one direction in the membrane plane, are less than or equal to the diameter of the optical waveguide (2). To position the tip (40) over the core (3) of the optical waveguide (2), optical methods can be used or the membrane and optical waveguide can be provided with locating elements.
    Type: Grant
    Filed: July 11, 1997
    Date of Patent: October 12, 1999
    Assignees: Institut fur Mikrotechnik Mainz GmbH, Omicron Vakuumphysik GmbH
    Inventors: Wilfried Noell, Alexander Ruf, Karsten Mayr, Peter Guthner
  • Patent number: 5963693
    Abstract: A light-emitting element is mounted on a first conversion element mounting portion prepared on a lead frame and resin-molded by using a mold. In this case, a focusing lens whose optical axis coincides with the major surface of the light-emitting element and a coupling portion in which a sleeve is fitted are integrally molded at once to mold a transmission section and an electronic circuit section. When these member are fixed in housings, and a ferrule holding an optical fiber is inserted in the sleeve fitted in a recess portion of the coupling portion, the optical fiber is optically coupled to the major surface of the light-emitting element. At this time, when the distal end portion of the sleeve is brought into contact with the abutment portion in the coupling portion, the end face of the optical fiber always coincides with the major surface of the light-emitting element, thereby realizing reliable optical axis alignment.
    Type: Grant
    Filed: August 26, 1997
    Date of Patent: October 5, 1999
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Toshio Mizue, Daisuke Takagi
  • Patent number: 5963680
    Abstract: In the fiber optic refrigerator of this invention the absorption of a photon of a preselected energy causes the emission of a luminescence photon of energy higher than that of the absorbed photon. This process requires the extraction of thermal energy from the fiber optic refrigerator, thus causing the cooling of any object or environment in thermal communication with the refrigerator.
    Type: Grant
    Filed: October 23, 1997
    Date of Patent: October 5, 1999
    Inventor: Marcos Y. Kleinerman
  • Patent number: 5959756
    Abstract: A 1.times.n optical deflection switch has an array of k transmissive light deflectors to switch an incident light beam into one of n=2.sup.k directions. The switch can steer the light through the deflectors into one of a plurality of beam directions, by selectively individually inserting them into the light path. One embodiment uses four glass rectangular blocks as light deflectors having parallel upper and lower surfaces oriented at a predetermined oblique angle to the incident light beam. The thicknesses of the blocks follow an increasing order in proportion to successive powers of 2, i.e. t, 2t, 4t and 8t, giving a total of 16 switching positions. Another embodiment uses two arrays of 4-block switches, and selectively activates blocks from either array to provide a 1.times.32 switch. Yet, another embodiment uses four stepped deflectors each having two selectable sections of dissimilar thicknesses to give a total of 15 switching positions.
    Type: Grant
    Filed: December 1, 1997
    Date of Patent: September 28, 1999
    Inventors: Barrie Keyworth, Rajiv Iyer, Neil Teitelbaum
  • Patent number: 5956359
    Abstract: The invention relates to a laser with a multi quantum well active layer in which a portion of the quantum well and barrier layers is provided with a compression stress, while another portion is provided with an oppositely directed tensile stress. Said stresses are overcompensated such that the net stress is a tensile stress. Preferably, the laser comprises one or several quantum well layers with a compression stress and a number of barrier layers with an excess tensile stress.
    Type: Grant
    Filed: June 14, 1996
    Date of Patent: September 21, 1999
    Assignee: Uniphase Opto Holdings, Inc.
    Inventors: Alfred R. Adams, Alistair T. Meney, James R. Downes, Adriaan Valster, Gerard A. Acket
  • Patent number: 5949930
    Abstract: A fiber optic rotation sensor system having improved scale factor stability includes an optically pumped gain fiber arranged to provide optical signals to an integrated optics chip connected to a fiber optic sensing coil. An optical coupler receives optical signals from the gain fiber and provides the optical signals to an optical fiber. The optical fiber is arranged to guide optical signals from the optical coupler along an optical path toward the integrated optics chip such that optical signals from the gain fiber are input to the fiber optic sensing coil to form counter-propagating waves therein. The counter-propagating waves traverse the sensing coil and then combine in the integrated optics chip to form a gyro output signal. A depolarizer is placed in the optical path between the first optical coupler and the integrated optics chip to prevent random changes in the state of polarization of optical signals propagating between the gain fiber and the integrated optic chip.
    Type: Grant
    Filed: July 23, 1997
    Date of Patent: September 7, 1999
    Assignee: Litton Systems, Inc.
    Inventors: Amado Cordova, Eric Lee Goldner, James R. Steele
  • Patent number: 5949934
    Abstract: An optical waveguide grating with radiative mode-coupling properties, with exceptional stability and reliability as an optical component, wherein the central wavelength of the rejection band has a low temperature dependence, due to the use of silica glass doped with germanium and boron for the core. The rejection bandwidth can be narrowed without increasing the grating length by forming the radiative mode-coupled optical waveguide grating in an optical waveguide wherein the mean relative refractive index difference of the core is greater than that of optical communication waveguides.
    Type: Grant
    Filed: March 26, 1997
    Date of Patent: September 7, 1999
    Assignee: Fujikura, Ltd.
    Inventors: Kensuke Shima, Michihiro Nakai, Hiroshi Hidaka, Kuniharu Himeno, Satoshi Okude, Akira Wada, Masaaki Sudoh, Tetsuya Sakai, Takuya Ienaka, Ryozo Yamauchi