Patents Represented by Attorney Robert L. Nathans
  • Patent number: 6380097
    Abstract: An aqueous thiourea-ammonia treatment is used to form a thin sulfurous film at the indium phosphide surface, having a thickness of less than one nanometer. The thiourea-ammonium hydroxide treatment can be used as is or immediately prior to deposition of cadmium sulfide for enhanced surface passivation. The thiourea-ammonium hydroxide treatment is entirely compatible with chemical bath deposition, molecular beam epitaxy, or metalorganic chemical vapor deposition of the cadmium sulfide.
    Type: Grant
    Filed: May 11, 1998
    Date of Patent: April 30, 2002
    Assignee: The United States of America as represented by the Secretary of the Air Force
    Inventors: Helen M. Dauplaise, Andrew Davis, Kenneth Vaccaro, Joseph P. Lorenzo
  • Patent number: 6229649
    Abstract: A first lens produces a Fourier transform of the wavefront distorted optical image at the Fourier transform plane. A phase encoded filter is positioned at the transform plane and a second filter is tandemly positioned with respect to the first filter, the second filter having a transmittance which is statistically similar to the reciprocal spatial frequency spectrum of the Fourier transform of the distortion function, to in turn produce an intermediate signal at the transform plane, which is now Fourier transformed by a second lens to recover the optical image having a substantially reduced degree of distortion.
    Type: Grant
    Filed: October 4, 1994
    Date of Patent: May 8, 2001
    Assignee: The United States of America as represented by the Secretary of the Air Force
    Inventors: Charles L. Woods, Jehad Khoury, Jack Fu
  • Patent number: 6195187
    Abstract: Large-scale switching array architectures for multiwavelength routing employ absorption-switched micro-ring resonator 2×2 switches at all optical cross-points of each of a plurality of series-connected waveguide crossbar matrix switches. The architecture eliminates detrimental waveguide crossovers. Two or four coupled micro-rings made from layered III-V or II-VI hetrostructure material can aid in maintaining cross-talk at very low levels while employing simple switch addressing methods.
    Type: Grant
    Filed: July 7, 1998
    Date of Patent: February 27, 2001
    Assignee: The United States of America as represented by the Secretary of the Air Force
    Inventors: Richard A. Soref, Brent E. Little
  • Patent number: 6154475
    Abstract: A family of lasers is provided which can be readily grown upon silicon wafer platforms, each laser having a highly doped stably strained SiGe or Ge collector layer formed upon a SiGe graded relaxed buffer layer in turn grown on the Si wafer, and an intrinsic strain-symmetric Ge--Si superlattice covered by a heavily doped stably strained SiGe emitter. The superlattice has numerous thin 8-15 atomic monolayers of interleaved Ge and Si atoms, enabling high stack heights.
    Type: Grant
    Filed: December 4, 1997
    Date of Patent: November 28, 2000
    Assignee: The United States of America as represented by the Secretary of the Air Force
    Inventors: Richard A. Soref, Lionel R. Friedman
  • Patent number: 6114994
    Abstract: A one-laser technique for optical time-delay beamsteering of a microwave phased-array antenna in transmit-and- receive modes. Arrays of reflective, fiber Bragg gratings are employed and a modulated, wavelength-tuned laser excites prism-shaped arrays of chirped or single-frequency gratings deployed inside a set of N parallel fibers. The fiber gratings can be replaced by waveguided gratings within a semiconductor chip for operation at high microwave frequencies.
    Type: Grant
    Filed: October 30, 1997
    Date of Patent: September 5, 2000
    Assignee: The United States of America as represented by the Secretary of the Air Force
    Inventors: Richard A. Soref, Henry Zmuda
  • Patent number: 6000283
    Abstract: The testing device is mounted on a portable stand so that it is easily placed near the aircraft engine to be tested. A source of pressure air is further required for the testing device. A portable source or a shop source is sufficient. The testing device has an output hose connected to a selected port for testing a gear box, sump, etc. The air pressure is adjusted going into the selected port and then the flow of air is measured. The reading obtained therefrom is then compared to a predetermined standard for that particular section to determine if there is a problem therein. If the problem is detected then corrective action is taken to eliminated the problem. This procedure is applied to as many ports as necessary to find the oil pressure problem.
    Type: Grant
    Filed: September 19, 1997
    Date of Patent: December 14, 1999
    Assignee: The United States of America as represented by the Secretary of the Air Force
    Inventor: Robert W. Wyatt
  • Patent number: 5991099
    Abstract: An imaging lens device at f/4 has zoomlike variable chromatic and spherochromatic correction for imagery in each of the astronomical U, B, V, and R bands. This lens system can thus take advantage of the full usable wavelength range of CCD cameras extending from 0.35-0.9 micrometers. A first triplet lens group effects the chromatic correction by altering separation between lens elements of the triplet while a second triplet lens group maintains a sharp image focus.
    Type: Grant
    Filed: February 23, 1998
    Date of Patent: November 23, 1999
    Assignee: The United States of America as represented by the Secretary of the Air Force
    Inventor: Mark A. Lundgren
  • Patent number: 5969226
    Abstract: A hardened steel ball presses against a vibrating sample to be subject to fretting. The amplitude and frequency of vibration can be precisely controlled by a stack of piezoelectric transducers. The biasing force of the steel ball against the sample can also be precisely controlled by a pulley supported weight that pulls against a movable mass coupled to the steel ball. The movable mass has sufficient inertial mass to eliminate the movement of the ball which might otherwise be produced in reaction to the vibration of the sample, which need not be absolutely flat.
    Type: Grant
    Filed: November 3, 1997
    Date of Patent: October 19, 1999
    Assignee: The United States of America as represented by the Secretary of the Air Force
    Inventors: James J. Wert, Miangui Xue, Pedro C. Bastias
  • Patent number: 5950303
    Abstract: A substrate stack is suspended within a stack holder to position upper and lower stack surfaces coplanar with upper and lower holder surfaces. Laminating heat and pressure is simultaneously applied to the upper and lower surfaces to laminate a carrier interconnect film to top and bottom stack portions simultaneously. Subsequent wet chemical processing of both stack edges may also be simultaneous to effect savings in manufacturing costs.
    Type: Grant
    Filed: April 3, 1998
    Date of Patent: September 14, 1999
    Assignee: The United States of America as represented by the Secretary of the Air Force
    Inventors: Paul A. McConnelee, Richard J. Saia, Kevin M. Durocher
  • Patent number: 5946152
    Abstract: Four loudspeaker voice coils are positioned in quadrature relationship, and a movable mirror support member is provided, having a mirror on a central hub portion, and having four outwardly extending orthogonal lightweight struts, each attached to an associated voice coil armature at a terminal strut portion. Jitter cancellation of a jittery incoming light beam directed at the mirror is effected by adjustment of tip/tilt AC generators coupled to the voice coils.
    Type: Grant
    Filed: March 24, 1998
    Date of Patent: August 31, 1999
    Assignee: The United States of America as represented by the Secretary of the Air Force
    Inventor: Jeffrey T. Baker
  • Patent number: 5940685
    Abstract: The wafer thickness of a CCD front illuminated silicon wafer is reduced to about ten to twenty microns, the Al substrate is removed and a 5-35 nanometer silicon oxide layer is produced on the thinned back of the silicon wafer followed by implanting boron ions within the back surface to a depth up to about ten nanometers. Furnace annealing the wafer is now carried out, and the Al substrate is redeposited to enable the formation of gate contacts.
    Type: Grant
    Filed: October 28, 1996
    Date of Patent: August 17, 1999
    Assignee: The United States of America as represented by the Secretary of the Air Force
    Inventors: Andrew H. Loomis, James A. Gregory, Eugene D. Savoye, Bernard B. Kosicki
  • Patent number: 5926148
    Abstract: First and second tandemly positioned electrically biased semiconductor members radiate microwave energy in response to the receipt of an excitation light beam having two wavelengths related to the bandgaps of the members. The projected microwave beam may be made more narrow and directional if two of the members are electrically biased at the same time. An inefficient frequency doubler generates the two wavelength beam enabling a single light beam to excite both members in a simple, rugged photoconductive antenna element.
    Type: Grant
    Filed: August 25, 1997
    Date of Patent: July 20, 1999
    Assignee: The United States of America as represented by the Secretary of the Air Force
    Inventors: David Da-Wei Liu, Paul H. Carr, Steven D. Mittleman
  • Patent number: 5923029
    Abstract: A pair of interleaved finger-like electrodes are positioned over a pyro-electric sheet of polyvinylidine fluoride and a pair of coatings are formed upon the electrodes having different optical reflectance, and as a result, a light beam energy absorption differential will be produced between the coatings and the resulting change in temperature in the sheet material under the electrodes will cause a voltage to be generated. A differential amplifier is connected across the electrodes to sense this voltage, indicative of the detection of an incoming laser light beam. A light chopper is positioned to interrupt the light beam directed at a portion of the pyro-electric sheet.
    Type: Grant
    Filed: September 22, 1997
    Date of Patent: July 13, 1999
    Assignee: The United States of America as represented by the Secretary of the Air Force
    Inventors: Thomas R. Sanderson, Richard C. Benson, Terry E. Phillips, Joseph J. Suter, Jay C. Poret
  • Patent number: 5919316
    Abstract: Numerous undesirable prior art epoxy beads or pads of metallization, employed to prevent unacceptable electrostatic charge buildup upon the solar cell coverglasses of solar cell array panels deployed in outer space, are eliminated by causing the charge conducting semiconductive coverglass layers to be wrapped around edge portions of each coverglass, to readily facilitate charge drainage of the electrostatic charge buildup.
    Type: Grant
    Filed: June 27, 1997
    Date of Patent: July 6, 1999
    Assignee: The United States of America as represented by the Secretary of the Air Force
    Inventors: Alexander Bogorad, Charles Kenneth Bowman, Jr., William Raymond Krummann, William Richard Hart
  • Patent number: 5920430
    Abstract: A lensless joint transform correlator optically determines the relative position of two pinholes placed in parallel arms of a Mach-Zehnder interferometer. The Fraunhaufer diffraction patterns combine to form a joint power spectrum signal in the joint transform plane. Because of the interference of the two pinhole signals, an encoded lens comprising a Fresnel zone is formed in the joint Fraunhaufer diffraction pattern which is illuminated with a plane wave, and the output signal is taken in the focal plane of the Fresnel zone and magnifies the input pinhole displacement by a factor of ten, enhancing its use in precision positioning servo systems for mask alignment.
    Type: Grant
    Filed: August 28, 1997
    Date of Patent: July 6, 1999
    Assignee: The United States of America as represented by the Secretary of the Air Force
    Inventor: Thomas J. Grycewicz
  • Patent number: 5909296
    Abstract: Curved arrays of lasers cause discreet narrow infra-red light beams to be rapidly projected within a wide field of view, without requiring mechanical motion of components. Transmitted and received light beams can be modulated with data to be transmitted between light beam transceivers for covert data communication purposes, or without data for use in collision avoidance systems.
    Type: Grant
    Filed: April 4, 1997
    Date of Patent: June 1, 1999
    Assignee: The United States of America as represented by the Secretary of the Air Force
    Inventor: Charles W. Tsacoyeanes
  • Patent number: 5903390
    Abstract: An all optical photorefractive holographic joint transform correlator provides a first correlation plane output port using two-beam coupling, and a second correlation plane output port employing four-wave mixing. With appropriate input beam intensity ratios, the first port output is capable of high discrimination, while simultaneously the second port offers a low discrimination output.
    Type: Grant
    Filed: October 4, 1996
    Date of Patent: May 11, 1999
    Assignee: The United States of America as represented by the Secretary of the Air Force
    Inventors: Jonathan S. Kane, Charles L. Woods, Jehad Khoury, George Asimellis
  • Patent number: 5886837
    Abstract: Method of assembling a large, lightweight, composite optical device such as a mirror or lens, includes providing a plurality of flat, lightweight optical element sections, fastening each optical element section to an associated frame segment to provide a plurality of optical elements and detachably fastening a plurality of the optical elements together in a manner causing all of them to lie in a single plane. After use, the device is disassembled and the optical elements are stacked in a compact mass to make them readily portable.
    Type: Grant
    Filed: June 26, 1998
    Date of Patent: March 23, 1999
    Assignee: The United States of America as represented by the Secretary of the Air Force
    Inventors: David J. Legare, David R. Jennings
  • Patent number: 5880491
    Abstract: A low-cost Si-based construction for optical and electronic bulk-heterostructure devices and multiple-quantum-well devices in which the active layers of the device are SiC or AlGaN or InGaN or InAlN. Material quality is high, and the MQW devices such as blue light lasers or LEDs have stable pseudomorphic layers with low defect densities. The low-cost large-area 3C SiC substrate is created by converting 100% of a 100-500 angstrom (.ANG.) layer of Si in a silicon-on-insulator wafer to 3C SiC with propane at 1300 degrees C. The SiO2 layer provides strain-free support for the "perfect" 3C SiC crystal layer. Direct-gap wurtzite nitride heterostructures, bulk or pseudomorphic MQW, are grown upon an (0001) 6H SiC epilayer on the (111) 3C SIC substrate, or directly upon the (111) 3C SiC substrate. For zincblende heterostructures, a (100) 3C SiC substrate is used.
    Type: Grant
    Filed: January 31, 1997
    Date of Patent: March 9, 1999
    Assignee: The United States of America as represented by the Secretary of the Air Force
    Inventors: Richard A. Soref, Fereydoon Namavar
  • Patent number: 5867615
    Abstract: Two modes in the waveguide are excited by establishing the input light polarization at forty-five degrees so that the modes can be excited equally. After propagating through the waveguide, the two modes are forced into one polarization by a polarizing fiber so that they can interfere, and the resulting novel straight channel modulator is compact and does not require strict single mode operation since the interference is in the polarizing fiber, which is a very good mode filter.
    Type: Grant
    Filed: July 22, 1997
    Date of Patent: February 2, 1999
    Assignee: The United States of America as represented by the Secretary of the Air Force
    Inventor: Yongqiang Shi