Abstract: An electrooptical analog-to-digital (A/D) converter. A laser beam is coupled into a waveguide which has been fabricated on an electrooptical crystal such as a lithium niobate LiNbO.sub.3 crystal. Electrodes are placed relative to the waveguide to form an electrooptical prism and an analog signal is fed to the electrodes. A modulated laser beam passing through the electrooptical prism is deflected in the plane of the waveguide in proportion to the applied analog signal. The deflected beam is expanded in the y-direction by diffraction-spreading or by a beam-spreading lens and falls on a ribbon-fiber, coded detector array. The array effectively codes the analog signal, translating the position of the deflected beam into a coded digital word which is representative of the magnitude of the analog signal.

Abstract: A method and means for x-ray lithography which utilizes means for producing n a vacuum system a high-temperature plasma from which soft x-rays are emitted. The x-rays pass through a mask exposing an x-ray resist on a substrate to produce the desired pattern on the substrate. The x-ray spectrum has a significant energy in the 1-5 keV range. These x-rays pass through the support layer of the mask, stop in the pattern material (gold) of the mask or, where the pattern material is lacking, are absorbed adequately by the x-ray resist. Since there is very little energy above 5 keV, there is little if any substrate damage due to the x-rays.

Abstract: Two input transducers launch oppositely-propagating acoustic surface waves on a piezoelectric substrate. The waves are compressed to a smaller beamwidth and then laterally confined in a diffused channel waveguide where non-linear interaction occurs at increased energy densities due to the beam compression. In one embodiment the beam compression is accomplished in multistrip couplers. In another embodiment, diffused horn-shaped channels are provided for compressing the beamwidth. Both piezoelectric and semiconductor convolvers are disclosed.

Abstract: In a scanning electron beam system wherein a primary beam of electrons is anned over the surface of a specimen and electron images are generated by collecting electrons scattered from the surface, an improved electron collector for selectively collecting the primary electrons that have suffered low loss in being scattered by the surface. Three symmetrically shaped mesh grids are arranged in front of a scintillator in the path of the backscattered electrons. The grids are disposed relative to each other and biased so that the electric fields permit passage of electrons within a narrow energy range. The scintillator is coated with a layer of tantalum and a layer of gold to provide thermal stability and resistance to damage from bombardment by high-energy electrons.

Abstract: A method for constructing systems of refractory layers for use in making gallium arsenide (GaAs) semiconductor devices, having gold as the conducting electrode, which devices are thermally stable when thermally stressed up to about 600.degree. C. for approximately 24 hours. The method forms refractory layers of either tantalum-platinum-tantalum, or tungsten-platinum-tungsten, or titanium tungsten-platinum to develop both the Schottky barrier to GaAs and the diffusion barrier between gold and GaAs. Each of the refractories are individually deposited, at specific temperatures in the range of 50.degree. C. to 175.degree. C., on a GaAs wafer within a vacuum. The metalized wafer cools to room temperature and is removed from the vacuum. Contacts are then typically defined on the wafer and the wafer is subsequently bonded.

Abstract: This disclosure is directed to a radioisotope photoelectric generator for producing electrical energy. The construction of the generator is similar to that of a well-known storage battery. The generator is composed of alternate layers of high-Z, (high atomic-number) and low-Z(low atomic number) material which are insulated by vacuum or other insulating material. Low-energy photons from a radioactive source interact predominantly with the high-Z material by the photoelectric process, ejecting photoelectrons whose energy extends up to the incident gamma-ray energy E. By selecting the high-Z material thickness to be less than one electron range (at energy E) and the low-Z material thickness to be more than one electron range, there is a net electron transfer from the high-Z plates to the low-Z plates because electrons are emitted predominantly from the high-Z plates and stop in the low-Z plates. After start-up, a potential difference will build up between the high-Z and low-Z plates.

Abstract: A surface acoustic wave (SAW) device formed by an unitary insulating, magostrictive ferrite, slab whose easy axis of magnetization is initially (prior to the application of a d.c. magnetic biasing field) perpendicular to the direction of SAW-wave propagation. For example, the easy axis of magnetization in a single-crystal lithium ferrite slab is the <111> axis. Therfore this axis is aligned perpendicular to the SAW wave propagation direction and parallel to the edges of the SAW device. Application of a dc magnetic field swings the magnetic moments such that they will be parallel with the SAW wave propagation. Materials useful in carrying out this invention are those which have (1) an easy axis of magnetization, (2) good insulator qualities and (3) the magnetostrictive property. A dc magnetic field is applied parallel with the SAW direction or perpendicular to the easy axis of the material in order to align the magnetic moments in the direction of the SAW wave propagation.

Abstract: Storage of thermal energy in a ternary mixture of salts which comprises from 22.5 to 26.5 weight percent of sodium chloride, from 18.5 to 22.5 weight percent of potassium chloride and from 53.0 to 57.0 weight percent of magnesium chloride.

Abstract: A method for converting coal to liquid hydrocarbons or oil-soluble solids mprises the steps of contacting said coal with oxygen for at least 15 minutes, at a temperature from about 90.degree. to about 225.degree. C., heating the oxidized coal to a temperature from about 250.degree. to about 450.degree. C., and maintaining the temperature for at least 15 minutes.

Abstract: A system and method for monitoring the operability of a radar system having phased-array antenna system. During an initial radiation pattern, a portion of the signals radiated from each radiating element of the array (except, in general, a center element, if any) is fed to a manifold network which combines the signals received from radiating elements which are symmetrically located with respect to the center of the array so that they differ by 180.degree. at the single manifold output. Radio-frequency energy is added to the manifold output to adjust it to approximately zero. While the radio-frequency energy added to the manifold network is maintained at this value, the phase-shift settings of pairs of radiating elements having equal amplitude-weighting are varied from the initial setting through 360.degree.. Failures are located by correlating the phase-shift settings and the adjusted output of the manifold network.

Abstract: A modular opening switch for high currents providing high current-carrying apacity, high voltage hold-off capability and very short opening time. The switch operates on the principle of an explosively generated pressure which ruptures and then drives paraffin radially through a cylindrical current conducting tube, so that the paraffin provides an electrically insulative barrier between the ruptured portions of the conducting tube. Alternate cutting and bending rings, between which insulating rings are placed, are disposed around the periphery of the conductor tube. The insulating rings are tapered at the periphery of the conductor tube to provide void spaces into which the paraffin is driven and firmly packed without voids or cracks which deteriorate the insulating property of the paraffin.

Abstract: An electrooptic switch in which one of four channel waveguides is selectively induced in a thin slab of electrooptic material by the application of an electric field between intersecting strips of electrodes disposed adjacent the top surface of the slab and other intersecting strips of electrodes disposed adjacent the bottom surface directly below the top surface strips. The electrode strips comprise (1) primary electrodes to which constant potentials are applied to induce optical paths partially through the slab and (2) switching electrodes, vertically displaced and electrically isolated from the primary electrodes, to which alternating potentials are applied to complete the desired optical path through the slab.

Abstract: Mixtures of metals are separated by forming salts of the metals which exhibit photoredox activity with an anion selected to provide insoluble salts at one oxidation state and soluble salts at another oxidation state, forming a solution of these salts with a solvent selected to permit a difference in solubility of salts dissolved at different oxidation salts and to be nonreactive with the nonsoluble salts, irradiating the solution with light at a wavelength which changes the oxidation state of the metal ion most susceptive to a change in oxidation state, and separating the insoluble salt formed thereby from the solution.

Abstract: A system for measuring, in conjunction with a GCA radar, the crab angle of n aircraft which is making its landing approach above a runway just prior to touch-down. Two doppler radars are placed, one on each side of the runway at equal spacings from the center line of the runway, with their antennas facing each other. The doppler radars function at very nearly the same frequency. The average doppler frequency of the echo received by each radar is determined and the frequencies are subtracted from each other. The difference in doppler frequency and the ground velocity of the aircraft are coupled to a computer which solves an equation to provide the value of the crab angle of the aircraft.The result can be radioed to the aircraft so that an adjustment in yaw can be made to zero the crab angle before touch-down.

Abstract: Collector plates for use in the second stage of a two-stage electrostatic ecipitator comprise plates having non-conducting surfaces to which a coating of low conductivity, typically between 300 and 150,000 ohms per square, is affixed. One embodiment of such plates typically comprises a rigid, non-conducting plastic material coated with a material of low conductivity. Another embodiment of the present invention comprises a metallic plate coated with an insulating material of high dielectric strength, typically with a dielectric constant of at least 3000, to which the above mentioned low-conductivity coating is affixed. The collector plates may be mounted in such a manner as to maintain the airflow through the second stage of the precipitator in a direction virtually parallel to the surface of the plates.

Abstract: Optical access and duplex couplers for multimode, fiber, data transmission ines. Access couplers are for use with multiterminal communication systems whereas duplex couplers allow a single fiber to be used for data transmission in both directions. Grooves of different depths and widths are etched into silicon along natural crystal planes to position fibers of different diameters and to provide reflective silvered surfaces. Optical communication signals pass through smaller-diameter transmission lines to larger lines. Light surrounding the smaller-diameter line from the larger line is reflected by the reflective surfaces. Thus, information may be received and added as desired.

Abstract: The formation of predominantly primary aliphatic perchlorates and trifluoethanesulfonates by reacting the corresponding silver salt with primary aliphatic halides in benzene at a temperature from about 5.degree. C. to about 50.degree. C. Primary aliphatic perchlorates and trifluoromethanesulfonates are excellent alkylating agents for amines, alcohols, and nitroalcohols.

Abstract: A single-mode optical fiber to a single-mode optical channel waveguide end-fire coupler. A single fiber held within a capillary tube and positioned by a micropositioner is adjusted for greatest light output and then secured by an epoxy to one end of a channel waveguide. The two elements are then secured in place in a slot in the capillary tube which prevents rotation of the waveguide relative to the single fiber.

Abstract: 1.

Abstract: An optical fiber acoustical sensor for detecting sound waves in a fluid mum. An optical fiber coil through which a light beam is transmitted is placed in a fluid medium. A sound wave propagating through the fluid medium and incident on the optical fiber coil changes the index of refraction of the optical fiber at the area of incidence. The index change causes a phase shift in the transmitted light which is detectable to denote the presence of the sound wave.