Abstract: A double-heterojunction diode fabricated on a single crystal fiber which is voltage and acoustically controlled so as to alternately be caused to be a laser, an optical amplifier, or a detector of optical signals. A preferred embodiment utilizes gallium arsenide (GaAs) and gallium aluminum arsenide (GaAlAs). The double-heterojunction diode when electronically powered with the right polarity becomes an injection amplifier, with the addition of an acousto-optic grating of suitable period for feedback becomes a laser, and with a suitably reversed potential and different acoustic period becomes a heterodyne detector. In a preferred embodiment, the device is utilized to insert frequency controlled coherent optical or infrared signals in both directions in a fiber waveguide, amplify those signals, and detect the heterodyne difference frequency.

Abstract: A thermal image camera (TIC) is disclosed which is sensitive to images hag wavelengths ranging substantially from the optical range to over 100 microns. Such images are hereinafter referenced as thermal images. The device further develops electron images by detection of more than 280,000 points in a plane. The subject system amplifies, integrates and stores image electrons on an insulator or dielectric grid, and gates the electron images foward on command onto a phosphor screen for direct viewing or onto electron sensitive photographic film or electrostatic recording paper for recording. The TIC is thus a three dimensional electronic data processing system having the capability of converting thermal images to electron images and further of recording images on photographic film or electrostatic paper. Means are provided for electronically storing one or more positive or negative images on an insulator grid with image intensity gain in the negative storage mode.

Abstract: A rotary motion sensor which employs a fiber interferometer more particularly comprises a system for driving a laser interferometer and electronically detecting the fringe shifts caused by rotation. In the preferred embodiment, a light emitting diode pumps a fiber laser which, in turn, drives a distribution waveguide. Coherent radiation from the distribution waveguide is partly backward-coupled by means of an acousto-optic grating into a reference optical waveguide. The acousto-optic grating also serves to offset the laser frequency by the acoustic drive frequency. Coherent radiation from the distribution waveguide is also coupled into each end of a multiple turn optical waveguide which serves as a fiber interferometer. A pair of directional couplers, one for the clockwise radiation and one for the counter-clockwise radiation, extract the coherent radiation from the fiber interferometer after the radiation has made at least one transversal of the multiple turn optical waveguide.

Abstract: A rotary motion sensor which employs an endless, closed-loop, multiple turn fiber interferometer. Coherent laser radiation is coupled into the fiber interferometer in both a clockwise and counter-clockwise direction and is permitted to traverse the entire interferometer waveguide many times so as to increase the cumulative phase shift due to multiple traversal. Means are provided for coupling the coherent radiation into and out of the fiber interferometer. Means are also provided for generating a pair of reference optical signals which are heterodyned with the extracted clockwise and couterclockwise signals to produce a pair of beat frequency signals at manageable, acoustic frequencies. The relative cumulative phase shift between the output acoustic signals and the circulating signals are the same so as to provide an extremely precise measurement of the rate of rotation.

Abstract: A method and apparatus for driving an optical waveguide with a coherent source of radiation. The apparatus includes means for providing a relatively high level of continuous wave (cw) coherent optical/infrared radiation in a closed waveguide, preferably traveling in one direction, means for scattering the optical radiation out of the closed waveguide, and means for collecting the scattered radiation in an adjacent waveguide for transmission to distant points. The cw coherent radiation is preferably generated within a single-frequency traveling-wave multi-turn Nd: YAG laser. A first waveguide is coupled at the ends to form a multi-turn laser or a closed loop system. The scattering means includes means for impressing a microwave modulating signal onto the first waveguide at the Bragg angle which serves to set up an effective optical grating within the first waveguide for scattering the laser beam.

Abstract: An imaging device for detecting reflections of millimeter waves from a tat. The imaging device includes a composite cathode for converting an input radiation image to an electron image by field emission, a focusing lens to demagnify the image, and an amplifier and storage plate spaced from the composite cathode for detecting, storing and transferring the electron image to a viewing screen or recording medium.

Abstract: This disclosure is related to electrical generators which utilize heating and cooling of separate points in a closed circuit ferrofluid system to generate electrical power directly from heat energy. The characteristic of ferrofluids to experience rapid change in their magnetic properties with temperature is utilized by placing a magnet around the circuit to create a self-pumping action of the ferrofluid through a solenoid to generate electric power.

Abstract: A fiber optical waveguide of the glass or single crystal types is formed into a loop or spiral with its ends joined to maximize optical or infrared single mode transmission. The waveguide is modified by doping or some other technique to lase when the loop or spiral is radiated with sufficient electromagnetic or optical energy. A single or multiturn ring laser is thus formed. The ring or spiral may be essentially in one plane. The frequency of lasing or oscillating is a factor of waveguide length. Two lasing frequency pickoffs spaced a maximum distance apart on the waveguide each extract a small portion of the energy from the waveguide propagating in both the clockwise (CW) and counterclockwise (CCW) directions. The lasing frequency in the CW and CCW directions is a factor of the rotation rate of the transducer, decreasing in the direction of rotation and increasing in the direction opposite to rotation.

Abstract: The camera includes an input focussing and image cycling system to alternly cycle between a thermal reference and a thermal image, onto a thermally sensitive layer. Means are provided for electronically controlled conversion of thermal images to electron images. Further means, defined in the camera, accomplish electronic image integration and storage. The output portion of the camera includes means to furnish image intensification, after integration and storage. Photographic or electrostatic film is pulled at a constant rate by a drive system positioned at the output of the camera, to expose film to the intensified image.

Abstract: A circuit for reducing the center frequency and bandwidth of microwave sils comprising a source of radar pulses, a Hall element for doubling frequency of signals derived in the circuit. The Hall element is connected in the feedback circuit of a comparator amplifier the purpose of which is to provide a difference signal between the radar input signal and the signal from the Hall element. A first RC network is provided at the output of the Hall element to balance the circuit derived signal about zero. A second RC network is provided at the output of the comparator amplifier to balance the output signal from the circuit about zero. The output signal, by action of the circuit elements, is a signal having its center frequency and bandwidth reduced by one half. Means are also provided to cascade circuits and to add radar target simulation to final output signal.

Abstract: A fiber acoustic waveguide comprising a single crystal fiber and a single ystal film deposited on the outer elongated surface of the single crystal fiber, wherein the single crystal film has a higher velocity of propagation than the single crystal fiber. The fiber acoustic waveguide has a delay that is directly proportional to its length, whereupon fixed lengths of the waveguide provided fixed delay.A fiber acoustic waveguide system is provided by connecting one end of the waveguide to driving transducer means for converting an electrical signal to an acoustic signal, and the other end of the waveguide to pickup transducing means for converting the transported acoustic signal from the waveguide back into an electrical signal.

Abstract: Photon images, typically but not necessarily, in the long or infrared wavngths are focussed upon the input face of a semiconductor plate. For an electronically controllable time input photon energy is converted to electrons free to move through a semiconductor substrate and integrated in thousands of PN diodes in the plane of the Plate. A deformographic film on the output face of the Plate is deformed according to the stored electron image. An optically reflective film is deposited over the deformographic film so that incident light from a first Schlieren Optic System scatters in accordance with the stored image and is focussed onto a further stage. The further stage includes an image intensifier which converts the scattered images to electron images, accelerates the electron images through electron optics and impacts them in an Image Storage Plate which amplifies the images and deforms a deformographic film-having an optically reflective surface.

Abstract: A broadband data modulation system for the transmission of amplitude and frequency modulation data with a bandwidth up to and greater than 500 MHz. The system involves the multiple heterodyning of microwave signals with infrared or optical signals. The data modulation system utilizes multiple passes of the infrared or optical signal through a crystalline material which also has an acoustic signal forming an acousto-optic grating. Fixed gratings are also imbedded in the crystal so as to aid in the guidance of the infrared or optical signal. The output of the crystal comprises an infrared or optical signal modulated with the desired data, which can be transmitted optically to a transponder, which can in turn convert the last-named infrared or optical signal into a transmitted correspondingly modulated RF signal.

Abstract: An Infrared Image Storage Plate for displaying and/or recording infrared ges having photon energy levels which are generally insufficient to release electrons from photocathode materials is described. The image storage plate includes a multi-layered structure, beginning from the face of incident infrared radiation: a conducting grid; a photoconductor layer; a layer of P type semi-conductor material having N type semiconductor islands thereon; a layer of dielectric material over the N type islands; a deformographic film; and a thin film of conductive material. To store an image therein a positive potential is applied to the thin conductive film and a negative potential is applied to the conductive grid. Upon the receipt of incident infrared radiation electrons are released from the photoconductor layer and are integrated by the PN junctions in the semiconductor material to thereby deform the deformographic film in accordance with the incident infrared image.

Abstract: In a radar test facility, a system for communicating between a radar target enerator which produces complex wideband radar data signals simulating static and dynamic targets and an angle simulation test array which comprises a plurality of infrared to microwave transponders. A single frequency traveling wave laser furnishes an infrared or optical source of radiation in a closed loop external to the laser crystal. A plurality of acousto-optic Bragg defractors are positioned in the path of the closed loop for gating the laser radiation out of the loop. Radio frequency simulations of radar signal reflections from such targets as aircrafts, missles, chaff, land, and the like, modulate the gated radiation in frequency and amplitude. Means are also provided for directing the modulated and gated radiation toward the infrared to microwave transponders. Each simulation is directed in angle so as to illuminate that part of the array from which it is desired to have the simulation appear to originate.

Abstract: An optical or photon image is converted by a photocathode to an electron ge. A semiconductor plate receives the electron image on a first side thereof. For an electronically controlled time, the image is integrated and stored in thousands of reversed biased PN junctions connected to micro-sized conductors, in the plate. An intensified image is then transfered from a second side of the plate at an electrically controlled time to adjacent moving film which is exposed to intensified images from the plate.

Abstract: A cascaded data modulation system for the transmission of amplitude and frequency modulation data with a bandwidth up to and greater than 500MHz. The system involves the multiple heterodyning of microwave signals with infrared or optical signals. The data modulation system utilizes the passing of an infrared or optical signal through several successive acousto-optic crystals. Curved and straight prisms are placed alternately between the crystals to guide the infrared or optical signal. The crystals carry acoustic signals which modulate the infrared or optical signal in amplitude and frequency. The output of the crystal system comprises an infrared or optical signal modulated with the desired data, which can be transmitted optically to a transponder, which can in turn convert the last-named infrared or optical signal into a transmitted correspondingly modulated RF signal.

Abstract: A wavefront flattener comprising an input surface, an output surface paral to said input surface, said input surface and said output surface comprising concentric rings of dielectric material, said concentric rings having a high dielectric constant at the center thereof dropping to a low dielectric constant at the outermost rings whereby electromagnetic radiation is crowded into the center of said input and output surfaces to cause a flattening of a curved electromagnetic radiation wavefront.