With Traveling Wave-type Tube Patents (Class 330/43)
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Patent number: 4693545Abstract: The invention provides a method for controlling the transmission of radiant energy through a light transmissive medium and an apparatus whereby the method can be effected.Type: GrantFiled: September 4, 1984Date of Patent: September 15, 1987Assignee: Westinghouse Electric Corp.Inventors: Tom Henningsen, Theresa A. Gould
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Patent number: 4687970Abstract: A digital cathode current control circuit for controlling the cathode current of a traveling wave tube (TWT) amplifier is disclosed. The cathode current control circuit includes circuitry for providing a comparison signal indicative of the occurrence and amplitude of TWT cathode current pulses; clocking circuitry responsive to the comparison signal for providing a clock signal delayed relative the occurrence of a cathode current pulse; comparison circuitry for comparing the comparison signal with predetermined reference signals indicative of a predetermined cathode current level, and for providing adjustment signals indicative of the adjustment of the TWT cathode current necessary to tend to achieve the predetermined cathode current; and counter circuitry clocked by the delayed clock signal for providing an output count in response to the adjustment signals.Type: GrantFiled: May 31, 1985Date of Patent: August 18, 1987Assignee: Hughes Aircraft CompanyInventors: Eugene F. Musslyn, Anand Kelkar
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Patent number: 4686485Abstract: 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: GrantFiled: November 7, 1985Date of Patent: August 11, 1987Assignee: The United States of America as represented by the Secretary of the NavyInventors: Lew Goldberg, Henry F. Taylor, Joseph F. Weller
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Patent number: 4674830Abstract: 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: GrantFiled: November 25, 1983Date of Patent: June 23, 1987Assignee: The Board of Trustees of the Leland Stanford Junior UniversityInventors: Herbert J. Shaw, Michel J. F. Digonnet
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Patent number: 4667162Abstract: 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: GrantFiled: June 28, 1984Date of Patent: May 19, 1987Assignee: Honeywell Inc.Inventors: Theodore W. Broberg, David D. Rathe
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Patent number: 4663596Abstract: 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: GrantFiled: May 1, 1985Date of Patent: May 5, 1987Assignee: Standard Telephones and Cables Public Limited CompanyInventor: John S. Heeks
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Patent number: 4661786Abstract: 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: GrantFiled: April 16, 1984Date of Patent: April 28, 1987Assignee: McDonnell Douglas CorporationInventor: Gerald M. Bender
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Patent number: 4658218Abstract: 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: GrantFiled: December 10, 1984Date of Patent: April 14, 1987Assignee: The United States of America as represented by the Secretary of the NavyInventors: Geraldine A. Kenney-Wallace, Edward L. Quitevis
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Patent number: 4656433Abstract: 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: GrantFiled: August 19, 1982Date of Patent: April 7, 1987Assignee: Hughes Aircraft CompanyInventors: James D. Franklin, Donald R. Dewhirst
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Patent number: 4649351Abstract: 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: GrantFiled: October 19, 1984Date of Patent: March 10, 1987Assignee: Massachusetts Institute of TechnologyInventors: Wilfrid B. Veldkamp, James R. Leger, Gary J. Swanson
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Patent number: 4628273Abstract: 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: GrantFiled: December 12, 1983Date of Patent: December 9, 1986Assignee: International Telephone and Telegraph CorporationInventor: Weldon R. H. Vlasak
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Patent number: 4626792Abstract: 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: GrantFiled: January 10, 1984Date of Patent: December 2, 1986Assignee: Cornell Research Foundation, Inc.Inventors: Richard L. Liboff, Kung C. Liu
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Patent number: 4614913Abstract: 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: GrantFiled: April 30, 1984Date of Patent: September 30, 1986Assignee: The United States of America as represented by the Secretary of the ArmyInventors: Thomas E. Honeycutt, Thomas G. Roberts
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Patent number: 4609876Abstract: 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: GrantFiled: April 26, 1984Date of Patent: September 2, 1986Assignee: Canadian Patents and Development LimitedInventors: Orson L. Bourne, A. John Alcock
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Patent number: 4596017Abstract: 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: GrantFiled: April 20, 1983Date of Patent: June 17, 1986Assignee: The United States of America as represented by the United States Department of EnergyInventors: Charles A. Fenstermacher, Keith Boyer
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Patent number: 4588957Abstract: 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: GrantFiled: June 9, 1982Date of Patent: May 13, 1986Assignee: International Business Machines CorporationInventors: Anne C. Balant, Daniel R. Grischkowsky
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Patent number: 4564787Abstract: 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: GrantFiled: March 20, 1985Date of Patent: January 14, 1986Assignee: The United States of America as respresented by the Administrator of the National Aeronautics and Space AdministrationInventor: Henry G. Kosmahl
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Patent number: 4559500Abstract: 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: GrantFiled: October 9, 1981Date of Patent: December 17, 1985Assignee: California Institute of TechnologyInventors: Iain S. McDermid, Thomas J. Pacala
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Patent number: 4559628Abstract: 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: GrantFiled: April 26, 1983Date of Patent: December 17, 1985Assignee: United Technologies CorporationInventors: Bruce V. Johnson, Roy N. Guile
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Patent number: 4554510Abstract: 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: GrantFiled: September 12, 1983Date of Patent: November 19, 1985Assignee: The Board of Trustees of Leland Stanford Junior UniversityInventors: Herbert J. Shaw, Michel J. F. Digonnet
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Patent number: 4551684Abstract: 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: GrantFiled: February 4, 1983Date of Patent: November 5, 1985Assignee: Spectra-Physics, Inc.Inventor: Anthony F. Bernhardt
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Patent number: 4549144Abstract: 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: GrantFiled: August 31, 1983Date of Patent: October 22, 1985Assignee: The United States of America as represented by the United States Department of EnergyInventor: Mark A. Summers
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Patent number: 4542510Abstract: 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: GrantFiled: August 26, 1983Date of Patent: September 17, 1985Assignee: Rockwell International CorporationInventor: Maurice D. Black, Jr.
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Patent number: 4529942Abstract: 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: GrantFiled: January 29, 1982Date of Patent: July 16, 1985Assignee: AT&T Bell LaboratoriesInventors: Chandra K. N. Patel, Earl D. Shaw
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Patent number: 4529944Abstract: 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: GrantFiled: June 29, 1982Date of Patent: July 16, 1985Assignee: The United States of America as represented by the Department of EnergyInventors: James H. Glownia, Robert K. Sander
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Patent number: 4529943Abstract: 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: GrantFiled: March 31, 1982Date of Patent: July 16, 1985Assignee: The United States of America as represented by the Department of EnergyInventors: E. Victor George, James C. Swingle
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Patent number: 4527132Abstract: 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: GrantFiled: June 28, 1982Date of Patent: July 2, 1985Assignee: Thomson CSFInventor: Jean P. Huignard
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Patent number: 4523315Abstract: 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: GrantFiled: April 9, 1982Date of Patent: June 11, 1985Assignee: AT&T Bell LaboratoriesInventor: Julian Stone
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Patent number: 4518934Abstract: 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: GrantFiled: February 16, 1982Date of Patent: May 21, 1985Assignee: AT&T Bell LaboratoriesInventor: Thirumalai N. C. Venkatesan
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Patent number: 4514698Abstract: 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: GrantFiled: April 11, 1980Date of Patent: April 30, 1985Assignee: TRW Inc.Inventors: Jack L. Blumenthal, John R. Ogren, Eugene V. Rutkowski, Marvin Appel
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Patent number: 4511850Abstract: 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: GrantFiled: January 26, 1982Date of Patent: April 16, 1985Assignee: The United States of America as represented by the United States Department of EnergyInventors: Leland G. Schlitt, Abraham Szoke
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Patent number: 4510455Abstract: 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: GrantFiled: May 4, 1982Date of Patent: April 9, 1985Assignee: The United States of America as represented by the United States Department of EnergyInventors: Donald Prosnitz, Roger A. Haas
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Patent number: 4506229Abstract: 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: GrantFiled: January 26, 1982Date of Patent: March 19, 1985Assignee: The United States of America as represented by the Department of EnergyInventors: Donald Prosnitz, Abraham Szoke
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Patent number: 4500855Abstract: 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: GrantFiled: June 10, 1982Date of Patent: February 19, 1985Assignee: University of Southern CaliforniaInventor: Jack Feinberg
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Patent number: 4500843Abstract: 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: GrantFiled: January 26, 1982Date of Patent: February 19, 1985Assignee: The United States of America as represented by the United States Department of EnergyInventors: Abraham Szoke, Donald Prosnitz
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Patent number: 4498051Abstract: 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: GrantFiled: July 9, 1981Date of Patent: February 5, 1985Inventors: Robert O. Hunter, David L. Fried
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Patent number: 4496876Abstract: 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: GrantFiled: September 23, 1982Date of Patent: January 29, 1985Assignee: The United States of America as represented by the Secretary of the NavyInventor: Leo Young
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Patent number: 4486885Abstract: 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: GrantFiled: April 3, 1984Date of Patent: December 4, 1984Assignee: Exxon Research & Engineering Co.Inventor: Azriel Z. Genack
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Patent number: 4484144Abstract: 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: GrantFiled: July 1, 1981Date of Patent: November 20, 1984Assignee: Kokusai Denshin Denwq Kabushiki KaishaInventors: Yukio Nakagome, Kitsutaro Amano, Takaya Yamamoto
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Patent number: 4481444Abstract: 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: GrantFiled: March 25, 1981Date of Patent: November 6, 1984Assignee: Litton Systems, Inc.Inventor: Robert M. Phillips
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Patent number: 4448832Abstract: 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: GrantFiled: April 25, 1983Date of Patent: May 15, 1984Inventor: William J. Kidwell
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Patent number: 4447789Abstract: 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: GrantFiled: March 8, 1983Date of Patent: May 8, 1984Assignee: Compagnie General d'ElectriciteInventors: Vincent Pugliese, Jean-Claude Farcy
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Patent number: 4431944Abstract: 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: GrantFiled: September 15, 1981Date of Patent: February 14, 1984Assignee: Thomson-CSFInventors: Christian Deville, Francis Payen
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Patent number: 4422046Abstract: 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: GrantFiled: June 23, 1980Date of Patent: December 20, 1983Assignee: The Perkin-Elmer CorporationInventors: Peter B. Mumola, Paul R. Yoder, Jr., Raul E. Casas, William M. Grossman
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Patent number: 4413208Abstract: 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: GrantFiled: June 30, 1981Date of Patent: November 1, 1983Assignee: Thomson-CSFInventor: Jean Paul Morizot
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Patent number: 4394623Abstract: 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: GrantFiled: January 27, 1981Date of Patent: July 19, 1983Inventor: Norman A. Kurnit
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Patent number: 4393332Abstract: 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: GrantFiled: September 5, 1980Date of Patent: July 12, 1983Assignee: Varian Associates, Inc.Inventor: Robert S. Symons
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Patent number: 4389617Abstract: 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: GrantFiled: March 13, 1981Date of Patent: June 21, 1983Assignee: The United States of America as represented by the United States Department of EnergyInventor: Norman A. Kurnit
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Patent number: 4387344Abstract: 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: GrantFiled: January 16, 1981Date of Patent: June 7, 1983Assignee: The United States of America as represented by the Secretary of the Air ForceInventor: Thomas W. Meyer
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Patent number: 4380074Abstract: 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: GrantFiled: October 1, 1979Date of Patent: April 12, 1983Inventor: Peter J. Walsh