With Traveling Wave-type Tube Patents (Class 330/43)
  • Patent number: 4686485
    Abstract: An apparatus for amplifying a laser beam through injection locking of a laser array by a single master laser is presented. The apparatus is comprised of a master laser which produces a beam that is shaped or focused onto a laser array facet which is further comprised of an array junction plane wherein the laser array is biased above threshold.
    Type: Grant
    Filed: November 7, 1985
    Date of Patent: August 11, 1987
    Assignee: The United States of America as represented by the Secretary of the Navy
    Inventors: Lew Goldberg, Henry F. Taylor, Joseph F. Weller
  • Patent number: 4674830
    Abstract: An amplifier for use with fiber optic systems comprises a neodymium YAG crystal placed in series with a signal-carrying optical fiber. The ND:YAG crystal is supplied by the optical fiber with both the signal to be amplified, and pumping illumination. The pumping illumination is coupled onto the optical fiber by a multiplexing coupler which is used to combine the signal to be amplified and illumination from a pumping illumination source onto a single optical fiber. The pumping illumination inverts the neodymium ions within the ND:YAG crystal. The signal to be amplified propagates through this crystal to stimulate emission of coherent light from the neodymium ions, resulting in amplification of the signal.
    Type: Grant
    Filed: November 25, 1983
    Date of Patent: June 23, 1987
    Assignee: The Board of Trustees of the Leland Stanford Junior University
    Inventors: Herbert J. Shaw, Michel J. F. Digonnet
  • Patent number: 4667162
    Abstract: Start up apparatus for starting the laser beams in a laser angular rate sensor with improved reliability and in a reduced amount of time.
    Type: Grant
    Filed: June 28, 1984
    Date of Patent: May 19, 1987
    Assignee: Honeywell Inc.
    Inventors: Theodore W. Broberg, David D. Rathe
  • Patent number: 4663596
    Abstract: In a coherent optical transmission system an input optical signal is amplified by being frequency down converted to an intermediate frequency, for example by means of a photodiode (1) and a reference optical local oscillator signal, and the photodiode output current is amplified in a GaAs FET wideband amplifier (6) and inserted on an optical carrier signal comprised by the reference signal by means, for example, of an integrated optical single sideband modulator (up converter) (7). By use of the same optical local oscillator to drive both the photodiode down converter and the integrated optic single sideband up converter, input/output coherence is ensured. The optical local oscillator may be comprised by a GaAlAs laser (3) stabilized to an "atomic" standard (4,5). Channel dropping/insertion may be carried out at the intermediate frequency, for example following the amplifier (6).
    Type: Grant
    Filed: May 1, 1985
    Date of Patent: May 5, 1987
    Assignee: Standard Telephones and Cables Public Limited Company
    Inventor: John S. Heeks
  • Patent number: 4661786
    Abstract: A method and apparatus for producing an optical phase array includes a plurality n of phase shifters associated with a plurality n of optical signals and a number (n-1) of independent feedback loops for generating electrical correction functions which are then combined through a transformation matrix of rank (n-1) or one in which the rows are linearly independent into a plurality n of phase shift signals for driving the phase shifters. Each phase shifter has its associated phase shift signal and independently modulates its optical signal to bring all of the optical signals into phase.
    Type: Grant
    Filed: April 16, 1984
    Date of Patent: April 28, 1987
    Assignee: McDonnell Douglas Corporation
    Inventor: Gerald M. Bender
  • Patent number: 4658218
    Abstract: A synchronization circuit couples a mode-locked oscillator-amplifier laser to a streak camera and Vidicon detection system. A sync signal from a mode-locker driver and a sync signal from a Nd:YAG pump laser act as basic circuit start signals. The circuit, with appropriate electronic timing delays, generates a Q-switch signal to the Nd:YAG laser to control the amplifier pump pulses to overlap with a dye laser pulse as it arrives in each stage of an optical amplifier chain.
    Type: Grant
    Filed: December 10, 1984
    Date of Patent: April 14, 1987
    Assignee: The United States of America as represented by the Secretary of the Navy
    Inventors: Geraldine A. Kenney-Wallace, Edward L. Quitevis
  • Patent number: 4656433
    Abstract: A laser amplifier buffer arrangement for selectively switching laser energy in a double pass laser amplifier. The buffer arrangement comprises a wedge of birefringent material which angularly separates incident laser energy into polarized components, and an electro-optic polarization switch which may be selectively controlled to circularly polarize the polarization components of light passing therethrough. A plane mirror is employed to reflect the polarized components back through the switch and wedge. The wedge and switch are aligned in a manner such that an arbitrarily polarized input beam is separated into two orthogonally polarizated components that traverse separate paths through the buffer. The polarized components are reflected back through the switch and wedge by the mirror which is aligned with the normal bisecting the polarization component separation angle.
    Type: Grant
    Filed: August 19, 1982
    Date of Patent: April 7, 1987
    Assignee: Hughes Aircraft Company
    Inventors: James D. Franklin, Donald R. Dewhirst
  • Patent number: 4649351
    Abstract: The disclosed apparatus includes a diffraction grating illuminated by a plurality of lasers. Apparatus is provided for summing the plurality of lasers coherently by, (a) phase locking the plurality of lasers and by, (b) diffracting the plurality of beams into a single beam. The diffraction grating has a configuration to generate upon illumination substantially equal intensities of diffraction orders corresponding to the number of lasers while suppressing higher unwanted orders. The phase locking can be accomplished by a single master laser, or by a cavity mirror to generate reference beams. Then, the output beams of the plurality of lasers propagating in the reverse direction are coherently superimposed by that grating. It is preferred that the diffraction grating be binary. Both one and two-dimensional diffraction grating arrays are disclosed.
    Type: Grant
    Filed: October 19, 1984
    Date of Patent: March 10, 1987
    Assignee: Massachusetts Institute of Technology
    Inventors: Wilfrid B. Veldkamp, James R. Leger, Gary J. Swanson
  • Patent number: 4628273
    Abstract: An optical amplifier having, for example, a photocathode to convert light to electrons, an electron multiplier, and a photo-emitter or light emitting diode to convert electrons to light. The electron multiplier may be made of magnesium oxide, silicon dioxide or silicon dioxide having bubbles therein. Alternatively, the electron multiplier may be an avalanche diode or other diode.
    Type: Grant
    Filed: December 12, 1983
    Date of Patent: December 9, 1986
    Assignee: International Telephone and Telegraph Corporation
    Inventor: Weldon R. H. Vlasak
  • Patent number: 4626792
    Abstract: A laser amplifier and method as disclosed wherein excitons in a pure insulator or semiconductor crystal are triggered by incident resonant laser radiation. The excitons are created by an external intermittent radiative source, and stimulated decay produces light output at a wavelength characteristic of the crystal. The radiative source produces light at the same wavelength as the light output produced by stimulated exciton decay, thereby producing an amplified output.
    Type: Grant
    Filed: January 10, 1984
    Date of Patent: December 2, 1986
    Assignee: Cornell Research Foundation, Inc.
    Inventors: Richard L. Liboff, Kung C. Liu
  • Patent number: 4614913
    Abstract: A laser weapon which has no boresighting problems in that only one laser is sed to perform all the functions of search, track, and negation. The laser weapon is made to operate in both a low power cw mode and a high energy pulsed mode about the boresight. This is accomplished here by the application of a material which can be rapidly switched from a transmissive to a reflective state so as to be able to utilize the same laser for search, travel, and negation; thus eliminating the need for boresight and requiring only alignment.
    Type: Grant
    Filed: April 30, 1984
    Date of Patent: September 30, 1986
    Assignee: The United States of America as represented by the Secretary of the Army
    Inventors: Thomas E. Honeycutt, Thomas G. Roberts
  • Patent number: 4609876
    Abstract: Laser pulse generation techniques are disclosed in which two competing non-linear processes, e.g. stimulated Brillouin scattering and laser-induced breakdown are employed in combination to generate a short laser pulse. Narrow linewidth UV radiation amplified to the millijoule level in a XeCl discharge module has been used to generate pulses of less than 200 picoseconds in duration.
    Type: Grant
    Filed: April 26, 1984
    Date of Patent: September 2, 1986
    Assignee: Canadian Patents and Development Limited
    Inventors: Orson L. Bourne, A. John Alcock
  • Patent number: 4596017
    Abstract: A method and apparatus for obtaining uniform, high-energy, large-volume electrical discharges in the lasing medium of a gas laser whereby a high-energy electron beam is used as an external ionization source to ionize substantially the entire volume of the lasing medium which is then readily pumped by means of an applied potential less than the breakdown voltage of the medium. The method and apparatus are particularly useful in CO.sub.2 laser systems.
    Type: Grant
    Filed: April 20, 1983
    Date of Patent: June 17, 1986
    Assignee: The United States of America as represented by the United States Department of Energy
    Inventors: Charles A. Fenstermacher, Keith Boyer
  • Patent number: 4588957
    Abstract: An optical pulse is passed through a nonlinear dispersive delay line, which chirps the pulse by the nonlinear process of self-phase modulation and simultaneously and interactively broadens the pulse by the process of group velocity dispersion. The broadened and chirped pulse is then passed through a linear dispersive delay line, which compresses the pulse to a width less than the original pulse. By making the optical pulse suitably intense, a single-mode optical fiber may act as the nonlinear dispersive delay line. A near-resonant atomic vapor cell or a grating pair may act as the linear dispersive delay line.
    Type: Grant
    Filed: June 9, 1982
    Date of Patent: May 13, 1986
    Assignee: International Business Machines Corporation
    Inventors: Anne C. Balant, Daniel R. Grischkowsky
  • Patent number: 4564787
    Abstract: The object of the invention is to provide a traveling wave tube with increased linearity to avoid intermodulation of signals being amplified. In a traveling wave tube 10, as shown in FIG. 1, the slow wave structure is a helix (18) including a sever (21). A dynamic velocity taper is provided by gradually reducing the spacing (26) between the repeating elements of the slow wave structure which are the windings of helix (18). The reduction takes place between Zo indicated by line 23 and Z.sub.s which coincides with the output point of helix (18) as indicated by the line (22). The spacing (26) begins to decrease at Z.sub.o and is decreased by up to about 5% at Z.sub.s. The spacing (26) between the repeating elements of the slow wave structure is ideally at an exponential rate because the curve (27), as shown in FIG. 3, increases from Z.sub.o to Zs the point of maximum efficiency and power, at an exponential rate. FIG. 3 shows a coupled cavity traveling wave tube having cavities 32 through 37.
    Type: Grant
    Filed: March 20, 1985
    Date of Patent: January 14, 1986
    Assignee: The United States of America as respresented by the Administrator of the National Aeronautics and Space Administration
    Inventor: Henry G. Kosmahl
  • Patent number: 4559500
    Abstract: A tuning arrangement (10) for a tunable laser comprises a single holographic grating (12) and two flat surface reflective mirrors (13 and 14). The beam (15) from the laser cavity is incident on the grating at a grazing angle for optimum beam expansion. The diffracted beam propogates from the grating to the first mirror (13), therefrom to the second mirror (14) and is reflected at the Littrow angle to the grating, whereat it is diffracted a second time and returned to the second mirror (14) for reflection to the first mirror (13). Therefrom it is reflected back to the grating. After undergoing a third diffraction it is directed back into the cavity for further amplification.
    Type: Grant
    Filed: October 9, 1981
    Date of Patent: December 17, 1985
    Assignee: California Institute of Technology
    Inventors: Iain S. McDermid, Thomas J. Pacala
  • Patent number: 4559628
    Abstract: A boundary-controlled aerodynamic window positioned adjacent the exit aperture of a gas laser is transparent to the laser beam emitted from the cavity of the laser. The boundary-controlled aerodynamic window is formed by a high velocity gas flow directed by a duct across the exit aperture for the laser beam isolating the low pressure region of the cavity from the high pressure of the atmosphere. The exit aperture is enlarged and an auxiliary gas flow injected along the sidewall of the duct adjacent the exit aperture to expand the thickness of the boundary layer. In a second embodiment, particulate matter is fixedly attached to the sidewall of the duct to increase the roughness of the wall surface. A third embodiment uses a plurality of nozzles, each injecting gas with a predetermined velocity.
    Type: Grant
    Filed: April 26, 1983
    Date of Patent: December 17, 1985
    Assignee: United Technologies Corporation
    Inventors: Bruce V. Johnson, Roy N. Guile
  • Patent number: 4554510
    Abstract: A fiber optic amplifier utilizes a crystal fiber of laser material to bidirectionally amplify light signals. This amplifier permits the application of both pumping illumination and the signal to be amplified to the end of the crystal fiber to avoid the disadvantages inherent in side pumping this fiber. End pumping is accomplished by taking advantage of the slow spontaneous fluorescence of the laser crystal to sequentially apply the pumping illumination and then the signal to be amplified to the crystal. This sequential application of signals is made possible through the use of a switchable coupler which allows light to be selectively coupled from either of a pair of input optical fibers to a single output optical fiber which is coupled to the crystal fiber. The pumping illumination is initially supplied to the crystal fiber to invert the ions within the crystal.
    Type: Grant
    Filed: September 12, 1983
    Date of Patent: November 19, 1985
    Assignee: The Board of Trustees of Leland Stanford Junior University
    Inventors: Herbert J. Shaw, Michel J. F. Digonnet
  • Patent number: 4551684
    Abstract: Amplified spontaneous emission is substantially reduced in a novel optical amplifier wherein the gain medium is disposed within a converging region of the coherent signal, which converging region terminates in a waist at or near a limiting stop or saturable absorber. In contrast to the converging coherent signal flux, the amplified spontaneous emission flux is nonconverging and therefore most of the latter is removed by a spatial filter or saturable absorber.
    Type: Grant
    Filed: February 4, 1983
    Date of Patent: November 5, 1985
    Assignee: Spectra-Physics, Inc.
    Inventor: Anthony F. Bernhardt
  • Patent number: 4549144
    Abstract: A laser pulse is injected into an unstable ring resonator-amplifier structure. Inside this resonator the laser pulse is amplified, spatially filtered and magnified. The laser pulse is recirculated in the resonator, being amplified, filtered and magnified on each pass. The magnification is chosen so that the beam passes through the amplifier in concentric non-overlapping regions similar to a single pass MOPA. After a number of passes around the ring resonator the laser pulse is spatially large enough to exit the ring resonator system by passing around an output mirror.
    Type: Grant
    Filed: August 31, 1983
    Date of Patent: October 22, 1985
    Assignee: The United States of America as represented by the United States Department of Energy
    Inventor: Mark A. Summers
  • Patent number: 4542510
    Abstract: A low inductance magnetic wiggler for use in electron beam type lasers generates a high intensity spatially periodic magnetic field. The wiggler is formed as a plurality of closed conductive loops having their centers spaced along a common axis. Adjacent loops are connected by a conductor extending parallel to the axis, the connecting conductors being positioned alternately on diametrically opposite sides of the loops.
    Type: Grant
    Filed: August 26, 1983
    Date of Patent: September 17, 1985
    Assignee: Rockwell International Corporation
    Inventor: Maurice D. Black, Jr.
  • Patent number: 4529944
    Abstract: Carbon Monoxide vapor is used to generate coherent, tunable vacuum ultraviolet radiation by third-harmonic generation using a single tunable dye laser. The presence of a nearby electronic level resonantly enhances the nonlinear susceptibility of this molecule allowing efficient generation of the vuv light at modest pump laser intensities, thereby reducing the importance of a six-photon multiple-photon ionization process which is also resonantly enhanced by the same electronic level but to higher order. By choosing the pump radiation wavelength to be of shorter wavelength than individual vibronic levels used to extend tunability stepwise from 154.4 to 124.6 nm, and the intensity to be low enough, multiple-photon ionization can be eliminated. Excitation spectra of the third-harmonic emission output exhibit shifts to shorter wavelength and broadening with increasing CO pressure due to phase matching effects.
    Type: Grant
    Filed: June 29, 1982
    Date of Patent: July 16, 1985
    Assignee: The United States of America as represented by the Department of Energy
    Inventors: James H. Glownia, Robert K. Sander
  • Patent number: 4529943
    Abstract: Apparatus for simultaneous laser pulse amplification and compression, using multiple pass Raman scattering in one Raman cell and pulse switchout from the optical cavity through use of a dichroic device associated with the Raman cell.
    Type: Grant
    Filed: March 31, 1982
    Date of Patent: July 16, 1985
    Assignee: The United States of America as represented by the Department of Energy
    Inventors: E. Victor George, James C. Swingle
  • Patent number: 4529942
    Abstract: In the interest of increased efficiency and gain of free-electron amplifier devices, means are provided for retarding electromagnetic radiation in such devices. This permits an electron beam pulse to catch up with a pulse of electromagnetic radiation and thus to interact repeatedly with electromagnetic radiation. Retarding means may be implemented, e.g., as one or several waveguides having suitable diameter and length; alternatively, resonant filters consisting essentially of wire meshes can be used.
    Type: Grant
    Filed: January 29, 1982
    Date of Patent: July 16, 1985
    Assignee: AT&T Bell Laboratories
    Inventors: Chandra K. N. Patel, Earl D. Shaw
  • Patent number: 4527132
    Abstract: A device is provided for the prolonged illumination of an object from an initial transitory illumination. This device comprises a laser whose cavity is closed by two total reflection mirrors; in the path of the intra-cavity radiation is disposed a photoexcitable interaction medium with index variation in the volume of which the transitory signal wave coming from the object and the intra-cavity radiation interfere; this interference generates in real time an index strata grating which diffracts a complex conjugate wave of the signal wave which returns to the object.
    Type: Grant
    Filed: June 28, 1982
    Date of Patent: July 2, 1985
    Assignee: Thomson CSF
    Inventor: Jean P. Huignard
  • Patent number: 4523315
    Abstract: A new Raman gain medium, comprising an optical fiber into which molecular gas has been diffused, is disclosed. This new medium combines the advantages of a fiber, i.e., long interaction path, low loss, controllable dispersion, and convenience in handling, with the large Raman wave number shift of the gas, i.e., 4136 cm.sup.-1 for H.sub.2 in silica. A laser made with such a medium can provide a relatively high power, tunable, coherent signal source in the near and far infrared regions.
    Type: Grant
    Filed: April 9, 1982
    Date of Patent: June 11, 1985
    Assignee: AT&T Bell Laboratories
    Inventor: Julian Stone
  • Patent number: 4518934
    Abstract: An optically integrated bistable device includes a semiconductor junction Fabry-Perot interferometer cavity and a pair of electrodes for applying a reverse-bias voltage to the junction to increase its light absorption. A capacitor is connected between one electrode and ground for eliminating spurious high-speed signals. A resistor is connected in series with the voltage source between the electrodes to decrease the back-bias in response to photocurrent for a negative feedback.
    Type: Grant
    Filed: February 16, 1982
    Date of Patent: May 21, 1985
    Assignee: AT&T Bell Laboratories
    Inventor: Thirumalai N. C. Venkatesan
  • Patent number: 4514698
    Abstract: A chemical laser including a laser pump which is relatively lightweight with no moving parts is provided. This produces a low pressure, regenerable, closed system for treating laser cavity exhaust gases to remove (i.e., pump) them from the system.The exhaust gases which emerge from the laser cavity of the chemical laser are pumped by a combination of condensation, cryogenic adsorption, and by reaction preferably with titanium, titanium-zirconium alloys, zirconium, tantalum, etc. These exhaust gases include hydrogen, deuterium and their halides, the halogens, oxygen, CO.sub.2, nitrogen and H.sub.2 O. This obviates the requirements for heavy equipment normally employed to produce a high vacuum in the laser cavity.
    Type: Grant
    Filed: April 11, 1980
    Date of Patent: April 30, 1985
    Assignee: TRW Inc.
    Inventors: Jack L. Blumenthal, John R. Ogren, Eugene V. Rutkowski, Marvin Appel
  • Patent number: 4511850
    Abstract: Method and apparatus for amplification of a laser pulse in a free electron laser amplifier where the laser pulse duration may be a small fraction of the electron beam pulse duration used for amplification. An electron beam pulse is passed through a first wiggler magnet and a short laser pulse to be amplified is passed through the same wiggler so that only the energy of the last fraction, f, (f<1) of the electron beam pulse is consumed in amplifying the laser pulse. After suitable delay of the electron beam, the process is repeated in a second wiggler magnet, a third, . . . , where substantially the same fraction f of the remainder of the electron beam pulse is consumed in amplification of the given short laser pulse in each wiggler magnet region until the useful electron beam energy is substantially completely consumed by amplification of the laser pulse.
    Type: Grant
    Filed: January 26, 1982
    Date of Patent: April 16, 1985
    Assignee: The United States of America as represented by the United States Department of Energy
    Inventors: Leland G. Schlitt, Abraham Szoke
  • Patent number: 4510455
    Abstract: Off-axis, two-dimensional designs for free electron lasers that maintain correspondence of a light beam with a "synchronous electron" at an optimal transverse radius r>0 to achieve increased beam trapping efficiency and enhanced laser beam wavefront control so as to decrease optical beam diffraction and other deleterious effects.
    Type: Grant
    Filed: May 4, 1982
    Date of Patent: April 9, 1985
    Assignee: The United States of America as represented by the United States Department of Energy
    Inventors: Donald Prosnitz, Roger A. Haas
  • Patent number: 4506229
    Abstract: Method for laser beam amplification by means of free electron laser techniques. With wiggler magnetic field strength B.sub.w and wavelength .lambda..sub.w =2.pi./k.sub.w regarded as variable parameters, the method(s) impose conditions such as substantial constancy of B.sub.w /k.sub.w or k.sub.w or B.sub.w and k.sub.w (alternating), coupled with a choice of either constant resonant phase angle or programmed phase space "bucket" area.
    Type: Grant
    Filed: January 26, 1982
    Date of Patent: March 19, 1985
    Assignee: The United States of America as represented by the Department of Energy
    Inventors: Donald Prosnitz, Abraham Szoke
  • Patent number: 4500855
    Abstract: An apparatus and method of producing a phase conjugate replica of a light beam involves internal reflection of the beam within a body of mixing material which lacks inversion symmetry. The orientation of the body relative to the incoming beam is adjusted such that at least one auxiliary beam splits off from the incoming beam, is internally reflected at least twice by the surface of the material and returns to the incoming beam within the material for scattering as an oppositely directed phase conjugate replica thereof.
    Type: Grant
    Filed: June 10, 1982
    Date of Patent: February 19, 1985
    Assignee: University of Southern California
    Inventor: Jack Feinberg
  • Patent number: 4500843
    Abstract: A method for simultaneous amplification of laser beams with a sequence of frequencies in a single pass, using a relativistic beam of electrons grouped in a sequence of energies corresponding to the sequence of laser beam frequencies. The method allows electrons to pass from one potential well or "bucket" to another adjacent bucket, thus increasing efficiency of trapping and energy conversion.
    Type: Grant
    Filed: January 26, 1982
    Date of Patent: February 19, 1985
    Assignee: The United States of America as represented by the United States Department of Energy
    Inventors: Abraham Szoke, Donald Prosnitz
  • Patent number: 4498051
    Abstract: An apparatus and process for pumping a lasing media (preferably krypton fluoride) over a 500 nanosecond period and thereafter compressing and focusing to a target with a final 10 nanosecond compression wave is disclosed. An exciting 10 nanosecond pulse is shaped in an overall rectangular shape with the major axes vertically aligned and this shaped beam directed upwardly and to the side of a normal extending between parallel and opposed mirrors at remote ends of a chamber. The chamber includes at the top thereof a plurality of stripper mirrors aligned along axes substantially normal to the beam path and tilted upwardly to shave successive segments off the upper portion of the beam. Beam passage opposite to the direction of stripper mirror emission produces a series of emitted shaved beam segments each spaced temporally in accordance with stripper mirror separation.
    Type: Grant
    Filed: July 9, 1981
    Date of Patent: February 5, 1985
    Inventors: Robert O. Hunter, David L. Fried
  • Patent number: 4496876
    Abstract: A wide band travelling wave amplifier including an input waveguide coaxia disposed about an interaction waveguide. Both waveguides are tapered with the same direction of increasing cross-section. The interaction waveguide is a high-pass filter while the input waveguide is a low pass filter. The input waveguide is positioned relative to the interaction waveguide so that each cutoff plane in the input waveguide corresponding to a given frequency, .omega..sub.c, is displaced in the direction of increasing cross-section from a cutoff plane in the interaction waveguide corresponding to .omega..sub.c where .omega..sub.c is any frequency in the frequency band of the amplifier. A slot, disposed between the cutoff planes corresponding to .omega..sub.c couples the .omega..sub.c frequency component of an input wave from the input waveguide to the interaction waveguide.
    Type: Grant
    Filed: September 23, 1982
    Date of Patent: January 29, 1985
    Assignee: The United States of America as represented by the Secretary of the Navy
    Inventor: Leo Young
  • Patent number: 4486885
    Abstract: A system is disclosed in which the phase of coherent light impinging on an absorbing cell is rapidly changed to produce a short amplified pulse of light.
    Type: Grant
    Filed: April 3, 1984
    Date of Patent: December 4, 1984
    Assignee: Exxon Research & Engineering Co.
    Inventor: Azriel Z. Genack
  • Patent number: 4484144
    Abstract: A semiconductor light amplifier having an active layer performing a light amplification function, in which the light amplification is performed intermittently by a stable clock timing synchronized with the clock timing of an input light pulse train to the active layer.
    Type: Grant
    Filed: July 1, 1981
    Date of Patent: November 20, 1984
    Assignee: Kokusai Denshin Denwq Kabushiki Kaisha
    Inventors: Yukio Nakagome, Kitsutaro Amano, Takaya Yamamoto
  • Patent number: 4481444
    Abstract: There is disclosed a traveling wave tube with a slow wave structure having means for frequency and directionally sensitive wave amplification. The slow wave structure includes a conductive helix coaxially mounted within a conductive tubular housing and a conductive support structure longitudinally disposed within the housing and extending transversely from the helix to the housing. In some embodiments, the support structure is combshaped and in one embodiment is a helical ridge wound in registration with and in the same sense as the helix. The pitch of the housing and a preselected parameter of the support structure are simultaneously varied along the length of the helix such that a wave at a given frequency band traveling along the slow wave structure in a first direction is preferentially amplified with respect to waves traveling in an opposite direction.
    Type: Grant
    Filed: March 25, 1981
    Date of Patent: November 6, 1984
    Assignee: Litton Systems, Inc.
    Inventor: Robert M. Phillips
  • Patent number: 4448832
    Abstract: A three dimensional woven composite is constructed of strands of graphite composite forming a basic geometric structure comprising a combination of regular octahedron and tetrahedron prisms alternately and regularly spaced. The framework of the geometric structure has one central intersection made up of twelve arms of strands and adjacent incomplete intersections of four or seven arms or strands.
    Type: Grant
    Filed: April 25, 1983
    Date of Patent: May 15, 1984
    Inventor: William J. Kidwell
  • Patent number: 4447789
    Abstract: The amplifier has a fluid active medium and contained in housing (1). The medium is excited by electric discharge in a resistance (4) constituted by a conductive layer deposited on an insulating support.Application to iodine lasers.
    Type: Grant
    Filed: March 8, 1983
    Date of Patent: May 8, 1984
    Assignee: Compagnie General d'Electricite
    Inventors: Vincent Pugliese, Jean-Claude Farcy
  • Patent number: 4431944
    Abstract: In the last section of a delay line having coupled cavities for a traveling-wave tube, the following parameters are progressively increased in the direction of propagation of the electron beam: the diameter of the opening provided for the passage of the electron beam, thus making it possible to ensure better transmission of the beam and consequently to ensure higher efficiency as well as lower heat build-up; the ratio (D.sub.2 -D.sub.1)/2 of the cavity nozzles; and the thickness of the walls which are common to two adjacent cavities.
    Type: Grant
    Filed: September 15, 1981
    Date of Patent: February 14, 1984
    Assignee: Thomson-CSF
    Inventors: Christian Deville, Francis Payen
  • Patent number: 4422046
    Abstract: An encoder for providing a conical array of temporally phased pulse beams. A pulse is inserted and continuously recirculated around an optical ring. The pulse is amplified during each circulation and a portion of the pulse is emitted at the end of each circulation. The encoder includes means for spatially separating each emitted pulse to provide a conical array of beams at a constant field angle relative to the optical axis of propagation.
    Type: Grant
    Filed: June 23, 1980
    Date of Patent: December 20, 1983
    Assignee: The Perkin-Elmer Corporation
    Inventors: Peter B. Mumola, Paul R. Yoder, Jr., Raul E. Casas, William M. Grossman
  • Patent number: 4413208
    Abstract: The invention relates to a high gain crossed field amplifier tube.Such a tube comprises in a vacuum enclosure 1 a cathode 2 and a delay line 3, itself constituted by an input line 31 whose height is less than that of the output line 32.The invention is applied to radio transmission systems.
    Type: Grant
    Filed: June 30, 1981
    Date of Patent: November 1, 1983
    Assignee: Thomson-CSF
    Inventor: Jean Paul Morizot
  • Patent number: 4394623
    Abstract: A regenerative ring amplifier and regenerative ring oscillator which function to feed back a portion of the Stokes signal to complete the ring cavity. The ring cavity configuration allows the CO.sub.2 laser pump signal and Stokes signal to copropagate through the Raman capillary waveguide amplifier. A Raman capillary waveguide amplifier is also provided in the return leg of the ring cavity to increase gain without increasing the round trip time. Additionally, the ring cavity can be designed such that the amplifier Stokes signal is synchronous with the mode-locked spikes of the incoming CO.sub.2 laser pump signal.
    Type: Grant
    Filed: January 27, 1981
    Date of Patent: July 19, 1983
    Inventor: Norman A. Kurnit
  • Patent number: 4393332
    Abstract: In a Gyrotron electron tube, oscillating motion perpendicular to the axis of a linear electron beam is produced by a helical component of magnetic field. The length along the beam of the helical field is critically chosen so that electrons at various radii from the axis all acquire equal transverse energy.
    Type: Grant
    Filed: September 5, 1980
    Date of Patent: July 12, 1983
    Assignee: Varian Associates, Inc.
    Inventor: Robert S. Symons
  • Patent number: 4389617
    Abstract: A combination regenerative ring and backward Raman waveguide amplifier and a combination regenerative ring oscillator and backward Raman waveguide amplifier which produce Raman amplification, pulse compression, and efficient energy extraction from the CO.sub.2 laser pump signal for conversion into a Stokes radiation signal. The ring cavity configuration allows the CO.sub.2 laser pump signal and Stokes signal to copropagate through the Raman waveguide amplifier. The backward Raman waveguide amplifier configuration extracts a major portion of the remaining energy from the CO.sub.2 laser pump signal for conversion to Stokes radiation. Additionally, the backward Raman amplifier configuration produces a Stokes radiation signal which has a high intensity and a short duration. Adjustment of the position of overlap of the Stokes signal and the CO.sub.2 laser pump signal in the backward Raman waveguide amplifiers alters the amount of pulse compression which can be achieved.
    Type: Grant
    Filed: March 13, 1981
    Date of Patent: June 21, 1983
    Assignee: The United States of America as represented by the United States Department of Energy
    Inventor: Norman A. Kurnit
  • Patent number: 4387344
    Abstract: A photon storage tube high power laser system having a repetitively pulsed or pumped laser therein and a photon storage tube. An initial pulse of electromagnetic radiation generated by the repetitively pulsed laser is directed into the storage tube for storage until amplified by redirection through the gain medium of the repetitively pulsed laser. As a result of appropriate adjustment of related focusing optics the repetitively pulsed laser acts only as a gain medium after the initial pulse generation. Continued storage and amplification of the initial pulse produces a high energy pulse of electromagnetic radiation which is subsequently output from the system.
    Type: Grant
    Filed: January 16, 1981
    Date of Patent: June 7, 1983
    Assignee: The United States of America as represented by the Secretary of the Air Force
    Inventor: Thomas W. Meyer
  • Patent number: 4380074
    Abstract: In accordance with the present invention, a laser device is formed on an integrated circuit substrate, such as a silicon chip by sandwiching a thin-film amorphous semiconductor between reflective electrodes. The upper electrode is made only partially reflective so that, when an operating potential is applied between the electrodes, a stimulated emission of light energy in the infrared range is observed and this emission occurs through the upper electrode. To form a light amplifier, the lower reflecting electrode is omitted, so that the amorphous semiconductor and the substrate form a heterojunction which has low infrared reflectivity. In operating the amplifier, a potential is applied between the upper electrode and the substrate to control amplification. Incident radiation passes through the upper electrode and into the amorphous semiconductor and substrate and, in the process, is amplified in accordance with the value of the applied potential.
    Type: Grant
    Filed: October 1, 1979
    Date of Patent: April 12, 1983
    Inventor: Peter J. Walsh
  • Patent number: 4376307
    Abstract: A semiconductor laser or traveling wave intensifier has an active layer between two passive semiconductor layers, and a strip-shaped electrode geometry. The active layer is uniform in thickness, while at least one of the passive layers within the strip-shaped geometry comprises a strip-shaped zone which contains portions having different refractive indices n.sub.1 and n.sub.2. According to the invention it holds that(n.sub.1 -n.sub.2) (d.sub.1 -d.sub.2)>0,wherein n.sub.1 is the refractive index of the portion which at least within said strip-shaped zone adjoins the active layer, d.sub.1 is the thickness thereof within the strip-shaped zone, and d.sub.2 is the thickness thereof beside the strip-shaped zone.
    Type: Grant
    Filed: May 15, 1980
    Date of Patent: March 8, 1983
    Assignee: U.S. Philips Corporation
    Inventors: Tullio E. Rozzi, Johannes H. C. Van Heuven
  • Patent number: 4364014
    Abstract: An optical modulator is provided in which one light beam is modulated by another. The modulator of the invention includes a saturable medium which is capable of amplifying an optical signal by stimulated emission of radiation. Two optical signals, in the form of two light beams are caused to pass through the medium and to emerge from the medium in amplified form. The beams, however, are caused to have different gains in the medium either by causing the beams to have different path lengths, or by other means. The beams are intercoupled by cross-saturation of the medium. Thus, any variations in the intensity of one of the beams causes a change in intensity in the other beam. Since one of the beams has a greater gain than the other, a small change in the intensity of one of the beams will produce a large change in the intensity of the other beam, thus producing in many aspects the optical analog of the transistor. The modulator of the invention shall be referred to herein as an "opto-optic" modulator.
    Type: Grant
    Filed: March 30, 1978
    Date of Patent: December 14, 1982
    Inventor: Richard W. Gray