Patents Represented by Attorney Melvin E. Frederick
  • Patent number: 4860302
    Abstract: A scanning beam laser pumped laser is disclosed which is capable of producing pulses of 50 or more microsecond duration with a repetition rate of 100 Hz or more and an energy content per pulse of 3 joules or more. Optics focus the output beam of the pumping laser onto the front surface of the pumped laser which may comprise a flowing dye cell. A rotating mirror synchronized with the pulse repetition rate of the pumping laser moves the spot across the dye in the pumped laser in a direction preferably orthogonal to the flow of dye therein. A spherical mirror behind the rear surface of the dye cell reflects radiant energy back toward the rotating mirror. Reflective radiance is turned therefrom to, in part, pass through the aperture of a beam-combining mirror. The small fraction of radiant energy passing through either a partially reflecting surface or a small aperature on the beam combining mirror enters a resonant cavity whose dimensions define the wavelength of the pumped laser.
    Type: Grant
    Filed: August 13, 1987
    Date of Patent: August 22, 1989
    Assignee: Avco Research Laboratory, Inc.
    Inventor: George S. Janes
  • Patent number: 4769820
    Abstract: At the receiving end or point at which a data or information carrying seed laser beam is to be received after traveling through a medium, a pump laser beam is propagated through the medium to the sending end of the medium at which point the now aberrated pump laser beam may be amplified if necessary and directed to and propagated through a waveguide composed of a suitable third order optically nonlinear medium. The data carrying seed laser beam is directed to and through the waveguide where it is phase conjugated and then through the medium in the direction opposite to that of the pump laser and arrives at the receiving end as an unaberrated laser beam. The data carrying laser beam and the pump laser beam have a frequency difference equal to the Stokes frequency shift of the waveguide material.
    Type: Grant
    Filed: October 16, 1987
    Date of Patent: September 6, 1988
    Assignee: AVCO Research Laboratory, Inc.
    Inventor: Richard B. Holmes
  • Patent number: 4762487
    Abstract: A pulsed combustor comprising at least one aerodynamic diode, a diffuser, fuel injectors, combustion chamber/duct, igniters, and muffler providing plug type flow with successive ignition and wave generation at the hot gas interface of the previous pulse. The downstream wave of each pulse propagates through the muffler whereas the upstream wave of each such pulse is at least partially reflected downstream with the diode(s) and diffuser minimizing reverse flow and maximizing pressure gain in the cumbustor.
    Type: Grant
    Filed: August 13, 1987
    Date of Patent: August 9, 1988
    Assignee: Gas Research Institute
    Inventor: Oswald L. Zappa
  • Patent number: 4673257
    Abstract: In accordance with one embodiment of the present invention, a controlling laser beam at a first wavelength is introduced into an interferometer such that one half of it contains the aberrations of the laser beam to be controlled and the other half is and remains undistorted. The aforementioned two halves of the controlling laser beam are combined at the output of the interferometer and then, together with the laser beam to be controlled at a second wavelength is introduced collinearly into a gas cell or phase corrector. Upon combination or interference of the two halves of the controlling laser beam the phase-front aberrations are translated to intensity modulations across the cross section of the beam.
    Type: Grant
    Filed: June 19, 1985
    Date of Patent: June 16, 1987
    Assignee: Avco Corporation
    Inventors: Mordechai Rokni, Allen M. Flusberg
  • Patent number: 4633103
    Abstract: A laser method of and apparatus for providing a wide variety of laser wavelenghts wherein a pump source of laser radiation is sequentially Strokes-shifted in two separate cells each containing a different molecular or atomic Raman active gas, wherein each cell is optimized to produce primarily first-Stokes radiation as by variation of focal length parameters and/or gas pressure, filter means are provided at the output of the first cell to reject the pump laser radiation and to pass the first-Strokes radiation of the first cell and further filter means are provided at the output of the second cell to reject the first-Stokes radiation of the first cell and pass the first-Stokes radiation of the second cell to provide a desired output laser radiation.
    Type: Grant
    Filed: May 4, 1983
    Date of Patent: December 30, 1986
    Assignee: Avco Everett Research Laboratory, Inc.
    Inventors: Howard A. Hyman, Daniel W. Trainor
  • Patent number: 4620305
    Abstract: Gaseous lasers and their operation wherein during operation in the saturated regime Zeeman reorientation collisions do not occur rapidly compared to the rate at which population is transferred out of their upper lasing level and there exists a static magnetic field of predetermined minimum strength inside the lasing region that is preferably at, or substantially at, the magic angle (approximately 54.70) with respect to the predominate polarization of the laser light in the lasing cavity.
    Type: Grant
    Filed: September 17, 1984
    Date of Patent: October 28, 1986
    Assignee: Avco Everett Research Laboratory, Inc.
    Inventor: Allen M. Flusberg
  • Patent number: 4617042
    Abstract: A method of producing a glass product requiring minimum fining wherein finely pulverized glass batch material is heated very rapidly in suspension in a hot gas stream to at least about its melting temperature in a heating chamber and directing it through a nozzle to impact on an impact surface in a separation chamber where the glass batch material is separated from the hot gas stream by adhering to the impact surface.Upon impact, the particles and/or molten material form a continuously flowing layer which flows over a flow surface as a molten layer into a pool of molten glass product in a collection zone. The melt flow over the flow surface is controlled to effect the immigration of gas therein to and then leave the exposed surface of the melt flow and simultaneously effect at least substantial reaction of the glass batch material before it reaches the collection zone.
    Type: Grant
    Filed: October 4, 1985
    Date of Patent: October 14, 1986
    Assignee: Gas Research Institute
    Inventor: David B. Stickler
  • Patent number: 4617046
    Abstract: A method of controlling NO.sub.x emissions from a combustion chamber wherein non-combustable particulate matter is heat processed. The particulate matter to be heat processed is entrained and dispersed in the products of combustion as a dispersed heat sink in a quantity and particle size to absorb heat by heat transfer from the products of combustion sufficient to cool the products of combustion from their peak temperature at a rate sufficient to kinetically limit the formation of NO in the products of combustion to a level which is a fraction of the NO equilibrium concentration of the products of combustion at their peak temperature. The fuel and oxidizer producing the products of combustion is burned in an equivalence ratio selected to result in substantially not more than small amounts of NO forming gases.
    Type: Grant
    Filed: October 4, 1985
    Date of Patent: October 14, 1986
    Assignee: Gas Research Institute
    Inventor: Finn A. Hals
  • Patent number: 4583023
    Abstract: A preferably fully impregnated dispenser cathode member or the like forming part of an electron tube, electron beam generator or the like is initially heated by any suitable means to a temperature sufficient for low level electron emission from its rear surface. A hot plate member of preferably equal size is disposed behind the cathode and can either be part of or the means for initially heating the cathode member or it can be heated with the cathode member to the aforementioned cathode member's rear surface low level emission temperature. A sustainer voltage is applied between the cathode member and the hot plate member sufficient to draw a current comprising electron flow from the cathode member to the hot plate member across the space separating them.
    Type: Grant
    Filed: July 23, 1984
    Date of Patent: April 15, 1986
    Assignee: Avco Everett Research Laboratory, Inc.
    Inventors: Herbert W. Friedman, Dennis A. Reilly
  • Patent number: 4321558
    Abstract: The working parts of a flowing gas laser are enclosed within an airtight housing comprising a first plenum separated from a second plenum. Blower means comprising one or more modules is provided with gas inlet means for receiving gaseous lasing medium from the second plenum and gas outlet means for exhausting the lasing medium to the first plenum. Means defining a lasing region are provided with gas inlet means for receiving lasing medium from the first plenum and gas outlet means for exhausting the lasing medium to the second plenum. The blower means provides a differential pressure across the lasing region sufficient to provide the desired flow of lasing medium through the lasing region. Due to the action of the blower means, lasing medium is caused to circulate from it to and through the lasing region and back to and through the blower means.
    Type: Grant
    Filed: March 11, 1980
    Date of Patent: March 23, 1982
    Assignee: Avco Everett Research Laboratory, Inc.
    Inventor: Oswald L. Zappa
  • Patent number: 4283686
    Abstract: In a pulsed gas laser, pulses of electrical or other energy are desirably converted in part into pulses of quantum mechanical pumping of the lasable gas, and unavoidably converted in part into pulses of heating of the lasable gas. According to this invention, efficiency and economy of operation are enhanced by exploiting the pulses of heating to propel and recirculate the gas through cooling means to freshen it thermally for further cycles of lasing, utilizing a structure comprising an acoustically tuned duct and an acoustic diode to establish proper phasing and direction of the pulsed and recirculating operation. The invention, although applicable to other gas lasers, is particularly applicable to electron beam ionized, electrical current sustained lasers. The invention reduces if not eliminates the cost, bulk and other disadvantages of a mechanical pump or other conventional recirculation equipment.
    Type: Grant
    Filed: March 21, 1979
    Date of Patent: August 11, 1981
    Assignee: Avco Everett Research Laboratory, Inc.
    Inventors: Jack D. Daugherty, Arthur R. Kantrowitz, George W. Sutton, Oswald L. Zappa
  • Patent number: 4264146
    Abstract: A laser mirror adapted to prevent astigmatism of reflected laser beams where the mirror is used for "folding" the laser beam such that the incident laser beam direction is not normal to the reflective surface of the mirror. This is accomplished by the provision of slots of specified dimensions in the rear surface of the mirror that in use are disposed parallel to the major axis of the laser beam's image on the mirror. In this manner, the mirror is provided with two bending stiffnesses, one in the direction of the major axis that is greater than that in the direction of the minor axis such that the bending due to heating of the mirror in the direction of both axes is made at least substantially equal.
    Type: Grant
    Filed: January 14, 1980
    Date of Patent: April 28, 1981
    Assignee: Avco Everett Research Laboratory, Inc.
    Inventor: George W. Sutton
  • Patent number: 4259988
    Abstract: A vortex-diode check valve comprises a short cylindrical working chamber with an axial inlet port entering axially through a first end wall at a short distance from the central portion of a second end wall and a tangential outlet port exiting tangentially through a circular side wall. The ratio of fluid flow resistances, between flows in the reverse and forward directions, is markedly increased by configuring at least one end wall as a flexible resilient diaphragm, permitting relative motion between the second end wall and the axial inlet port.
    Type: Grant
    Filed: September 17, 1979
    Date of Patent: April 7, 1981
    Assignee: Avco Everett Research Laboratory, Inc.
    Inventor: Param I. Singh
  • Patent number: 4229708
    Abstract: This invention is directed towards a scalable X-ray laser comprising means for providing an active medium of lithium-like atoms or ions, means for producing in the active medium a population of low density ions in an excited intermediate metastable state and a visible or near infrared laser to stimulate X-ray lasing by resonant or non-resonant antistokes Raman process to the ground state of the ions. The irradiation of the ions by the laser provides phased or traveling wave excitation which produces the desired directivity. Production of the metastable state is provided by directing energy from a suitable source, such as a high power short pulse laser beam, onto a target material and causing it to radiate as a black body, filtering this radiation to derive radiation in the soft X-ray region, and directing this filtered radiation into the lithium-like vapor.
    Type: Grant
    Filed: April 8, 1977
    Date of Patent: October 21, 1980
    Assignee: Avco Everett Research Laboratory, Inc.
    Inventors: Siva A. Mani, Howard A. Hyman, Jack D. Daugherty
  • Patent number: 4203078
    Abstract: Apparatus for and method of operating a laser wherein a discharge is produced preferably in a high pressure lasing gaseous mixture comprising at least one suitable first gaseous species capable of providing an excited state which has a finite probability of being ionized and a molecular second gaseous species having a capability for attaching electrons to form negative ions. The gaseous mixture may, for example, comprise argon, neon, helium, xenon, krypton or a metal vapor such as mercury as the first species and, for example, hydrogen iodide, carbon tetrachloride, bromine, iodine or fluorine as the second species. A buffer gas such as, for example, argon, helium or neon may also be used. The discharge is produced by means of an electron beam and an electric field. The discharge resulting from the application of the electric field heats secondary electrons produced by the electron beam to an energy level sufficient to make excited states.
    Type: Grant
    Filed: May 6, 1977
    Date of Patent: May 13, 1980
    Assignee: Avco Everett Research Laboratory, Inc.
    Inventors: Jack D. Daugherty, Jonah H. Jacob, Joseph A. Mangano
  • Patent number: 4171518
    Abstract: There is described a method of and apparatus for regulating the output power of lasers of the type utilizing a heated high velocity flowing gas. The method and apparatus comprise a plurality of separate sources of the gas in combination with a segmented diffuser section wherein at least one but not all of the diffuser sections can be blocked to selectively permit use of all or less than all of the gas sources, thereby permitting regulation of output power by regulating the mass flow through the optically resonant cavity disposed between the sources of gas and the diffuser.
    Type: Grant
    Filed: October 1, 1968
    Date of Patent: October 16, 1979
    Assignee: Avco Corporation
    Inventors: John A. Denner, Jr., Richard A. Allen
  • Patent number: 4123798
    Abstract: This invention relates to apparatus and methods for providing a high-density memory for electrical data and more particularly, to such a memory wherein data are represented by patterns of charge written and read by electron beam means at addressed locations.
    Type: Grant
    Filed: December 5, 1977
    Date of Patent: October 31, 1978
    Assignee: Avco Everett Research Laboratory, Inc.
    Inventors: Francis J. Cook, Frederick E. Kline
  • Patent number: 4116589
    Abstract: Extracorporeal blood pumping apparatus for use, for example in cardiopulmonary bypass procedures, left ventricle assist, hemodialysis and the like. The pulsatile pump apparatus may comprise an elongated driver balloon and a similar blood pumping balloon positioned side by side in a rigid casing or housing having preferably a one-way air valve. The inlet and/or outlets of both balloons are off-set and sloping ballon end portions are provided, inter alia, to minimize folding and/or rubbing during use. The driver balloon is provided with a port for coupling to a pressure-vacuum source and the blood pumping balloon is provided with an inlet port and an outlet port and both balloons are of such a cross sectional size and construction as to provide non-occlusive action by the blood pumping balloon.
    Type: Grant
    Filed: April 15, 1977
    Date of Patent: September 26, 1978
    Assignee: Avco Corporation
    Inventor: Michael L. Rishton
  • Patent number: 4092405
    Abstract: Method of and apparatus for non-equilibrium chemical kinetic separation of deuterium from hydrogen are described wherein hydrogen with its normal abundance of deuterium and an appropriate reactant, bromine, are supplied to a deuterium reaction vessel wherein they are vibrationally excited by, for example, being exposed to a volumetrically scalable ionizing-sustainer electrical discharge effective to provide vibrational excitation of the H.sub.2 and HD following which selective intermolecular vibration-vibration energy pumping occurs giving conditions effective to produce an HBr/DBr product mixture. The ionizing-sustainer discharge is effective to generate vibrational excitation from which follows chemical reactions that produce DBr and HBr at such relative rates that the mixture is enhanced in deuterium content relative to said content of the entering hydrogen stream. For the production of heavy water, the DBr and HBr are then dissolved in water.
    Type: Grant
    Filed: June 1, 1976
    Date of Patent: May 30, 1978
    Assignee: Avco Everett Research Laboratory, Inc.
    Inventors: Charles W. von Rosenberg, Jr., James J. Ewing, Robert E. Center, Hao-Lin Chen
  • Patent number: 4079340
    Abstract: Herein described is an unstable resonator optical cavity for lasers which may have a square, rectangular or the like spherical concave primary reflection surface at one end of the cavity that intercepts the optical axis of the cavity at or adjacent to one of its corners and a more or less similar square, rectangular or the like spherical convex feedback reflection surface at the opposite end of the optical cavity that intercepts the optical axis at or adjacent to one of its corners arranged and adapted to define an unstable resonator cavity.
    Type: Grant
    Filed: June 21, 1976
    Date of Patent: March 14, 1978
    Assignee: Avco Everett Research Laboratory, Inc.
    Inventors: Melvin M. Weiner, George W. Sutton