Patents Examined by B. R. R. Holloway
  • Patent number: 4849983
    Abstract: Process and apparatus for obtaining an excimer and application to a laser.The apparatus comprises a compression chamber (9), compressor (11) for compressing the gaseous mixture R+XY+M in the compression chamber (9), an expansion chamber (3) communicating at least one opening (23,23a) with the compression chamber (9), a vacuum pump (25) for producing within the expansion chamber (3) a pressure well below that prevailing in the compression chamber (9), the pressure difference between the compression and expansion chambers, the surface of the opening and the volume of the compression chamber being such that the gaeous mixture entering the compression chamber undergoes a supersonic adiabatic expansion with a Mach number at least equal to 10 and electrodes (27, 29, 27a, 29a) for producing an electric discharge (E) in the expansion chamber (3), downstream (x) of the opening (23, 23a) FIG. 2.
    Type: Grant
    Filed: December 18, 1987
    Date of Patent: July 18, 1989
    Assignees: Commissariat a l'Energie Atomique, Centre National de la Researche Scientifique
    Inventors: Michel Boivineau, Christophe Jouvet, Francois Piuzzi
  • Patent number: 4847849
    Abstract: A laser includes a discharge tube formed from one piece and penetrating, with play, into an anode chamber on one side and into a cathode chamber on the other side, the anode and cathode chambers having a thermal expansion coefficient different from that of the discharge tube. Bellows are hermetically welded by their first ends to the anode and sealed by a glass bead to the discharge tube at their second ends.
    Type: Grant
    Filed: March 16, 1987
    Date of Patent: July 11, 1989
    Assignee: Asulab S.A.
    Inventor: Jurg Steffen
  • Patent number: 4847843
    Abstract: Optical fibres comprised of a halide glass incorporating color centers, for example fluoride fibres, can behave as a laser or an amplifier when maintained at a low temperature, typically 77.degree. K., and optically pumped. A laser may be comprised by a length of such a fibre (1) wound on a spool (2) and disposed in liquid nitrogen (4), the ends of the fibre are outside of the coolant and associated with input and output mirrors (5,6) which define the extremities of a lasing cavity. An optical pumping signal (7) is provided by a laser (8), for example a Krypton ion laser operating in the visible range. The output of the fibre laser is in the infra-red. Higher gain than with conventional color center lasers is achieved due to the longer interaction length and cooling problems are overcome.
    Type: Grant
    Filed: February 1, 1988
    Date of Patent: July 11, 1989
    Assignee: STC PLC
    Inventors: Kevin C. Byron, Michael G. Scott, Wilson Sibbett
  • Patent number: 4847845
    Abstract: A semiconductor laser includes a semiconductor substrate on which a first semiconductor layer forming a rectifying junction is disposed, a groove extending through the first layer and into the substrate, a first cladding layer disposed on the semiconductor substrate in the groove, an active layer provided on the first cladding layer in the groove, and a second cladding layer provided directly on the active layer and opposite the first semiconductor layer, with an interposed gap void of solid material or an interposed gap and a current blocking material having only negligible parasitic capacitance disposed at spaced locations in the gap.
    Type: Grant
    Filed: December 9, 1987
    Date of Patent: July 11, 1989
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Etsuji Omura, Hirofumi Namizaki
  • Patent number: 4845716
    Abstract: An arrangement for the wavelength-selective internal intensity modulation and radiation pulse generation of high power CO.sub.2 lasers, in a high-power CO.sub.2 laser is forced to operate in the resonator at a freely selectable but fixed wavelength by means of a frequency-selective element and highly angle-selective gas discharge tubes. The possibility of rapidly Q-switching is provided by a special interferometer arrangement of variable reflectivity, functioning as an uncoupling element. The arrangement may furthermore be used for the rapid stabilization of the laser power.
    Type: Grant
    Filed: November 26, 1986
    Date of Patent: July 4, 1989
    Assignee: VEB Kombinat Feinmechanische Werke Halle
    Inventors: Manfred Poehler, Gisbert Staupendahl, Richard Wittig
  • Patent number: 4843609
    Abstract: Disclosed is an optical integrated circuit for heterodyne detection. The optical integrated circuit comprises: a semiconductor substrate; an active region of a semiconductor laser; two optical waveguides; a photo detector; and an optical coupler composed of the waveguides. The emission of light from the active region of the semiconductor laser is synthesized as local oscillation light with the transmission light. The synthesized light travels through the optical coupler and is detected by the photo detector.
    Type: Grant
    Filed: December 28, 1987
    Date of Patent: June 27, 1989
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Jun Ohya, Yasushi Matsui
  • Patent number: 4841539
    Abstract: A relatively high power gas laser includes a laser discharge tube formed of stacked alternating cooling wafers and ceramic wafers, the cooling wafers being provided with recesses set back from the discharge channel of the laser discharge tube.
    Type: Grant
    Filed: April 10, 1987
    Date of Patent: June 20, 1989
    Assignee: Siemens Aktiengesellschaft
    Inventors: Guenther Hahn, Hans Krueger, Herbert Lamprecht, Werner Seiffarth
  • Patent number: 4841538
    Abstract: A CO.sub.2 gas laser device comprises a plurality of divided cathode electrodes disposed in a linear row extending transversely across a high-speed flow of a gas containing CO.sub.2, and parts of the cathode electrodes producing negative glow are disposed at the same height as anodes at a downstream position. Additionally, a device for controlling the distribution of gas flow velocity, which functions doubly as means for creating turbulent flow, and a preliminary discharge electrode are disposed on the upstream side of the cathode electrodes, the former being set at a height position corresponding substantially to that of the middle portions of the cathode electrodes.
    Type: Grant
    Filed: November 10, 1988
    Date of Patent: June 20, 1989
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Satoru Yanabu, Hideomi Takahashi, Eiji Kaneko, Koichi Yasuoka
  • Patent number: 4841532
    Abstract: A method for producing a semiconductor laser which comprises sequentially depositing a lower cladding layer, an active layer, and an upper cladding layer on a substrate, forming a V shaped groove in the deposited layers at least reaching the lower cladding layer, the groove extending in a direction perpendicular to the direction between the surfaces that are to become resonator end surfaces, growing a semiconductor layer having a larger energy band gap than that of the active layer in the groove while retaining the V shaped groove, and cleaving the substrate and layers along the V shaped groove.
    Type: Grant
    Filed: November 10, 1987
    Date of Patent: June 20, 1989
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Hisao Kumabe, Wataru Susaki
  • Patent number: 4841533
    Abstract: A semiconductor laser device containing a laser oscillation-operating area comprising a superlatticed quantum well region which is composed of layers of GaAs alternating with layers of Al.sub.x Ga.sub.1-x As (0<x.ltoreq.1), where each of the layers has a thickness of several molecular layers or less;optical guiding layers consisting of Al.sub.y Ga.sub.1-y As (x.ltoreq.y.ltoreq.1) sandwiching the quantum well region, where the AlAs mole fraction varies continuously; andcladding layers covering the optical guiding layers.
    Type: Grant
    Filed: October 17, 1986
    Date of Patent: June 20, 1989
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Toshiro Hayakawa, Takahiro Suyama, Masafumi Kondo, Kohsei Takahashi, Saburo Yamamoto
  • Patent number: 4839903
    Abstract: Triaxial ring laser gyroscopes have three interconnecting cavities which provide many paths along which discharge can be initiated, and consequently it has been found that it is difficult to achieve the correct discharge. It is therefore proposed to align the desired discharge paths with the electrostatic fields which exist due to the voltage differences between the cathode and each one of the six anodes to enhance the initiation of the correct discharge.
    Type: Grant
    Filed: June 26, 1986
    Date of Patent: June 13, 1989
    Assignee: British Aerospace Public Limited Company
    Inventors: Graham J. Simms, David J. Guppy
  • Patent number: 4839900
    Abstract: A buried type semiconductor laser device comprising a multi-layered epitaxial growth crystal including a striped laser-oscillation operating area on a semiconductor substrate, wherein said laser-oscillation operating area contains a buffer layer having the same polarity as said substrate, an active layer and a cladding layer having a polarity different from that of said substrate, said laser-oscillation operating area being sandwiched between one part of the burying layer and another part of the burying layer, which are disposed on said substrate and which have a polarity different from that of said substrate, through said substrate or a diffusion region having an impurity with the same polarity as said substrate so as to electrically isolate said burying layer from said cladding layer, thereby maintaining ineffective current flowing from said cladding layer to said burying layer at a low level even when current injected into said device is increased.
    Type: Grant
    Filed: August 15, 1986
    Date of Patent: June 13, 1989
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Toshihiko Yoshida, Haruhisa Takiguchi, Shinji Kaneiwa, Hiroaki Kudo, Sadayoshi Matsui
  • Patent number: 4837773
    Abstract: A discharge excitation type short pulse laser device is provided with a preliminary ionization circuit, the effeciency of preliminary ionization of which is remarkably improved. The laser device comprises a main discharge circuit including first and second main electrodes which are confronted with each other in a laser medium, main discharge capacitor means for storing energy for main discharge, and a discharge starting high voltage switch; and a preliminary ionization circuit connected to said high voltage switch, said preliminary ionization circuit including a discharging gap for preliminary ionization, a preliminary ionization capacitor and an inductance.
    Type: Grant
    Filed: October 31, 1988
    Date of Patent: June 6, 1989
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Hitoshi Wakata, Mitsuo Inoue, Yukio Sato, Kenyu Haruta, Haruhiko Nagai
  • Patent number: 4836953
    Abstract: The Figure of Merit of titanium-doped sapphire crystal article suitable for use as a tunable laser is enhanced by treating the article at a temperature of about 1750.degree. C. to 2025.degree. C. in an atmosphere containing at least about 20 volume percent hydrogen.
    Type: Grant
    Filed: February 9, 1988
    Date of Patent: June 6, 1989
    Assignee: Union Carbide Corporation
    Inventor: Milan R. Kokta
  • Patent number: 4834339
    Abstract: A hydraulic jack system used for lifting and lowering heavy loads such as machine tools comprises a lower cylindrical member, a solid ram member mounted within the cylindrical member and an outer sleeve member having affixed thereto a lifting slab and fitting over the lower cylindrical member. A hydraulic injection hose forces fluid into the lower cylindrical tube causing the ram member to rise and thus lift the outer sleeve member and the flange on which the load rests. The hydraulic injection hose has an adjustable valve which allows not only for injecting fluid at a rate to raise the ram member and thus the load as quickly as desired, but also allows fluid to flow back through the fluid injection hose at a desired rate such as to lower the load through the force of gravity as quickly as desired.
    Type: Grant
    Filed: January 14, 1988
    Date of Patent: May 30, 1989
    Inventor: Ward Clarke
  • Patent number: 4833684
    Abstract: A semiconductor laser of the distributed feedback (DFB or DBR) type is bounded in the longitudinal direction by end surfaces at right angles to the active region and at least one of these end faces is provided with an anti-reflection layer in order to suppress Fabry-Perot modes. In order to obtain an optimum effect, an anti-reflection layer of hafnium oxide is used. The invention is used with great advantage in lasers of the DCPBH (Double Channel Planar Buried Hetero-structure) type.
    Type: Grant
    Filed: November 1, 1988
    Date of Patent: May 23, 1989
    Assignee: U.S. Philips Corp.
    Inventors: Henricus C. J. Krekels, Pieter I. Kuindersma
  • Patent number: 4833687
    Abstract: A distributed feedback semiconductor laser is provided with an optical waveguide having first and second straight-bar portions and a bending portion. The pitch of the grating in the case of light passing through the bending portion is a little longer than that in the case of light passing through the first and second straight-bar portion in order to shift the phase of the light transmitted along the optical waveguide by .lambda./4 where .lambda. is the oscillation wavelength, thereby generating single longitudinal mode laser light.
    Type: Grant
    Filed: December 16, 1986
    Date of Patent: May 23, 1989
    Assignee: Sony Corporation
    Inventor: Shoji Hirata
  • Patent number: 4831631
    Abstract: A laser transmitter comprising a semiconductor laser, and an external resonator in the form of an optical directional coupler characterized by feedback device being allocated to a first waveguide of the directional coupler and also a second feedback device allocated to the second waveguide of the coupler, each of the feedback devices returning a portion of the radiant energy in their respective waveguides back along the waveguide to the directional coupler and the output power of the transmitter being taken from the second waveguide of the directional coupler. Preferably, the section of each of the waveguides between the directional coupler and the respective feedback means has a different length with the difference being substantially in the magnitude of the length of the semiconductor laser. Preferably, the waveguides are strip waveguides integrally formed on a substrate and can include a modulator, as well as having the semiconductor laser also integrated on the substrate.
    Type: Grant
    Filed: July 23, 1987
    Date of Patent: May 16, 1989
    Assignee: Siemens Aktiengesellschaft
    Inventors: Klaus M. Haeussler, Julius Wittmann, Gisela Gaukel, Franz Auracher