Abstract: An electricity generator is disclosed having electrically conductive, counter-rotating collectors arranged coaxially with a magnetic field extending radially from an axis of rotation. The collectors intersect the radial magnetic field perpendicularly and are electrically connected to each other to conduct current flow in opposite directions to balance the interaction between current flow in the collectors and the magnetic field.

Abstract: An integrated circuit multiplexer comprises a waveguide having an interior cavity, first RF input port, and a first and second output ports; a dielectric structure positioned in the cavity; an RF input feed attached to the dielectric structure that extends through the RF input port; a first RF output feed attached to the dielectric structure that extends through the first RF output port; a second RF output feed attached to the dielectric structure that extends through the second RF output port; a first resonator pair mounted to the dielectric structure between the RF input feed and the first RF output feed, and electrically connected to the waveguide; and a second resonator pair mounted to the dielectric structure between the RF input feed and the second RF output feed, and electrically connected to the waveguide so that the first and second resonator pairs are generally coplanar.

Abstract: A low-cost high-resolution staring infrared imaging sensor for viewing a large Field Of Regard (FOR) while integrating over a small IFOV to detect small dim targets by subdividing the FOR into a plurality of internal optical paths without the use of mechanically-movable parts. Each of the plurality of internal optical paths may be further subdivided by a plurality of steerable micro-mirrors to reduce the IFOV and enhance long-range target acquisition capability. The sensor includes a primary lens for accepting infrared radiation from a Field Of Regard (FOR), a plurality of primary mirrors each disposed to reflect a portion of an FOR image along a different optical path, a secondary lens in each optical path to focus the FOR image portion onto a secondary mirror for reflection along a preselected direction, and a tertiary lens in each optical path to focus the FOR image portion onto an image detector array.

Abstract: The present invention has applications that include detecting color variation in a region, for example, color variations due to temperature changes in an area of ocean water, and, in a more specific application, detecting bioluminescence of certain organisms known to attach themselves to various objects. In one aspect of the invention, an acousto-optic tunable filter hyperspectral imaging system is moved across the region to collect a series of images in which each image represents the intensity of light at a different wavelength. In one embodiment, the acousto-optic tunable filter hyperspectral imaging system includes a motion platform for positioning the acousto-optic tunable filter hyperspectral imaging system over successive Y-coordinates of a region in a direction substantially parallel to a direction of motion of the motion platform.

Abstract: Radar tubes are assessed based upon an observation that faulty radar pulses have a significantly increased content of undesired high frequency components in their cathode current sensed at the cathode lead of an operating radar transmitting tube. The invention exploits this observation in a simple, relatively low-cost device that can be built into a radar system to be put under test. The current at the transmitting tube's cathode is high-pass filtered to pass only those frequency components known to be indicative of faulty transmitting tubes. The filter output is converted into an analog output having an amplitude proportional to the amplitude of the high frequency voltage components passing through the filter. The high-pass output is smoothed and is fed to an analog-input, digital-output threshold amplifier. The threshold amplifier provides a TTL output that indicates whether its smoothed input amplitude represents a good radar pulse or a faulty pulse.

Abstract: A tunable spectral source includes an enclosure having first and second apertures; an optical dispersive element positioned in the enclosure; and multiple pixel source elements that are individually controllable for selectively directing one or more broadband light signals through the first aperture to irradiate the optical dispersive element. Each of the broadband light signals irradiates the optical dispersive element at a unique angle of incidence. The optical dispersive element disperses the broadband light signals into spectral component signals at dispersion angles that are dependent upon the angle of incidence of each broadband light signal that irradiates the optical dispersive element. The portions of the spectral component signals that are emitted through the second aperture are determined by selecting one or more particular pixel source elements to irradiate the optical dispersive element.

Abstract: A method for communicating with a decreased probability of detection by an unintended listening party uses frequency hopping and two substantially identical linearly polarized antennas whose polarization vector is synchronized to frequency. Synchronization of polarization with frequency is accomplished through specifically designed conductor-backed spiral antennas. For these conductor-backed spiral antennas, a change in frequency is synchronized to a change in the polarization vector of the communication signal. Since the receiving station will be programmed to alter its reception frequencies in accordance with those being transmitted, the second spiral antenna will automatically change its polarization upon making these frequency changes. A rapid change of polarization increases the difficulty in detecting and intercepting the communication by parties for whom the message was not intended.

Abstract: The electrical response phenomenon of electrostrictive polymers is used to harvest electrical power from the general movement of objects such as from human walking motion, for example. In a preferred embodiment of the invention, the polymer material is incorporated into the soles of footwear and is either full- or partial-wave rectified and then if desired converted to a direct current (DC) voltage level for suitable battery charging and the like.

Abstract: An automated system determines the minimum resolvable temperature difference of a thermal imager with respect to a background scene. The system comprises: a) a thermal energy for generating thermal signals; b) at least one pattern mask for transforming the thermal signals into thermal image signals; c) a thermal imager for detecting and transforming the thermal image signals into transformed signals; and d) a computer for determining the minimum resolvable temperature difference of the thermal imager using the transformed signals. A display coupled to the computer may be used to present the minimum resolvable temperature difference in human readable form.

Abstract: This invention describes an improved method of making electrical contact to porous silicon using intercalated conductive materials. The intercalation process may use gaseous, liquid or solid components to form conductive contacts to the silicon structures of the porous silicon. The intensity of the light emitted by porous silicon layers and devices can therefore be increased by the improved electrical interconnection between the mechanically, chemically and thermally fragile porous silicon and the device electrodes. The intercalation process uses conductive materials that interpenetrate the structures of the porous silicon thereby providing the improved electrical properties. Increasing the surface area over which electrical contact is made increases the junction area which allows increased electrical current flow across the junction. The increased electrical current flow across the junction provides an increased number of electrical charge carriers undergoing radiative recombination.

Abstract: A surface enhanced Raman scattering structure may be used for detecting analytes such as organic contaminants in air and aqueous environments, and metallic and anionic contaminants in water. The structure is fabricated by etching a surface of a glass substrate to form a roughened surface; creating an adhesion layer on the roughtened surface; forming metal islands, such as gold, silver, or copper, on the adhesion layer to create a composite structure; and placing the composite structure in a thiol solution to form a self-assembled monolayer over the metal islands. The thiol solution is selected to attract an analyte of interest. The roughened surface enhances the SERS response of the structure and preferably has an average surface roughness that does not exceed about 2500 Å and a periodicity that does not exceed about 12.5 microns.

Abstract: A solid state modulated ultraviolet laser comprises a laser diode for generating modulated optical energy, a waveguide upconversion laser for converting a portion of the modulated optical energy to upconversion optical energy, and a waveguide sum frequency generator for combining the modulated optical energy and the upconversion optical energy to generate a modulated ultraviolet signal.

Abstract: A method for fabricating complementary vertical bipolar junction transistors of silicon-on-sapphire in fewer steps than required for true complimentary vertical bipolar junction transistors is disclosed. Initially a thin layer of silicon is grown on a sapphire substrate. The silicon is improved using double solid phase epitaxy. The silicon is then patterned and implanted with P+-type and N+-type dopants. Subsequently a micrometer scale N-type layer is grown that acts as the intrinsic base for both an PNP transistor and as the collector for an NPN transistor. The extrinsic base for the NPN is then formed and the emitter, collector and ohmic contact regions are next selectively masked and implanted. Conductive metal is then formed between protecting oxide to complete the complementary vertical bipolar junction transistors.

Abstract: A photo-lithographic mask includes a flexible, optically transparent body having an optically transmissive first surface for receiving an optical signal, and a second surface opposite the first surface having grooves for internally reflecting first portions of the optical signal and for allowing second portions of the optical signal to be transmitted through the second surface when the second surface is pressed against a wafer. The body consists essentially of silicone. The grooves have a saw tooth profile that are configured at an angle that exceeds the critical angle of the silicone with respect to the direction of the incoming optical signal.

Abstract: Disclosed is an optical modulating device capable of use as a light-valve, display, optical filter or Fabry-Perot cavity, for example. The device lends itself to batch processing, and is compatible with monolithic integration with silicon, silicon-germanium, silicon-on-sapphire (SOS) or silicon-on-quartz (SOQ) advanced microelectronic technology (NMOS, PMOS and CMOS) for integrated control circuitry, electrical addressing, system interfacing, and the like. The device forgoes the complexities of liquid crystal constructions, and avoids the need to position and fix piezoelectric spacers within layers of the device. The invention includes first and second transparent layers that are disposed to oppose one another. Metallic layers are disposed upon the inwardly facing surfaces of the transparent layers and these are arranged to oppose each other. Spectral coupling layers are disposed upon the outwardly facing surfaces of the transparent layers opposite of the metallic layers.

Abstract: A method for making a self-aligned FET with an electrically active mask comprises the steps of forming a semiconductor layer on an insulating substrate, forming an electrically nonconductive oxide layer on the semiconductor layer, forming an electrically conductive metal layer on the oxide layer, patterning the metal layer and the oxide layer to form an electrically active gate on semiconductor layer, introducing dopants into the semiconductor layer to form a source region and a drain region masked by the metal gate, and illuminating the source and the drain regions with a pulsed excimer laser having a wavelength from about 150 nm to 350 nm to anneal the source region and the drain region.

Abstract: A liquid crystal array and associated drive circuitry are monolithically formed on a silicon-on-sapphire structure, and are fabricated by a method comprising the steps of: a) forming an epitaxial silicon layer on a sapphire substrate to create a silicon-on-sapphire structure; b) ion implanting the epitaxial silicon layer; c) annealing the silicon-on-sapphire structure; d) oxidizing the epitaxial silicon layer to form a silicon dioxide layer from a portion of the epitaxial silicon layer so that a thinned epitaxial silicon layer remains; e) removing the silicon dioxide layer to expose the thinned epitaxial silicon layer; f) fabricating an array of pixels from the thinned epitaxial silicon layer wherein each of the pixels includes a liquid crystal capacitor; and g) fabricating integrated circuitry from the thinned epitaxial silicon layer which is operably coupled to modulate the pixels.

Abstract: An active sonar system with improved noise-limited performance in littoral regions with reverberation. This invention solves the active sonar comb-waveform power-limitation problem by introducing for the first time a system employing a new comb waveform herein denominated the triplet-pair comb waveform. Ambient noise-limited performance of the system of this invention is superior to that of systems employing other Doppler-sensitive waveforms such as the geometric comb waveform. Reverberation-limited performance of the system of this invention is slightly inferior to that of systems employing other Doppler-sensitive waveforms but this invention eliminates much of the range ambiguity problems seen with other non-comb waveforms.

Abstract: A wideband antenna system comprises a stack of m antennas, where m is a positive integer, and m≧2. Each antenna includes: a) an electrically insulating substrate; b) opposed first and second radio frequency elements mounted to the substrate; c) a ground feed electrically connected to the first radio frequency element; d) an excitation feed electrically connected to the second radio frequency element; and e) a ground plane mounted to the substrate of the mth antenna. The radio frequency elements of each antenna collectively have a unique total area and are mounted to the electrically insulating substrate. The radio frequency elements of the ith antenna provide a ground plane for the kth antenna, where i and k are positive integers, 1≦k≦(i−1), and 2≦i≦m. The total area of the first and second radio frequency elements of the ith antenna is greater than the total area of the first and second radio frequency elements of the kth antenna.

Abstract: A Q-switched neodymium laser may be operated in the 0.9 &mgr;m [( &lgr;1)] band at relatively high gain levels. The laser uses a birefringent filter which provides selective discrimination for wavelengths near 1 &mgr;m [(&lgr;2)] and prevents parasitic lasing in that wavelength region. The filter includes a specific wavelength dependent crystal quartz wave plate in combination with a linear polarizer. The linear polarizer is placed between two mirrors which define a laser cavity. The wave plate provides exactly 2 full waves of retardation at the desired wavelength &lgr;1 in the 0.9 &mgr;m band, and exactly 1.75 waves of retardation at wavelength &lgr;2 near the center of the 1 &mgr;m band for one pass. A Q-switching device such as a Pockels cell is positioned in the laser cavity to selectively control a pulsed emission at &lgr;1.