Abstract: A fiber-optic acoustical sensor system includes a light source, an elongate optical cable conducting light from the light source to an optical acoustical transducer located at a distance from the light source along this cable, and a polarizer at the acoustical transducer. The sensor system includes a polarizer providing orthogonally-polarized light along the optical cable to the polarizer located adjacent to the transducer. Because of the polarizer adjacent to the transducer, disturbances of the optical cable and resulting polarization perturbations of the light transmitted along this cable do not affect the optical acoustical transducer. The acoustic transducer is responsive to sound energy to provide an optical return signal indicative of this sound energy.

Abstract: Modular apparatus for packaging and interfacing a planar photodiode with an optical fiber terminated in a ferrule. An elongated terminal pin protrudes from a header of a generally-cylindrical housing. The ferrule end of the fiber is received at the opposed end of the housing and aligned with a disk-shaped photodetector fixed to the end of the pin interior to the housing. A wire is bonded to a surface of the photodetector and, via the conductive casing of the header, to the housing to provide a miniaturized single-pin pigtailed modular arrangement that is readily adaptable for automated manufacturing process.

Abstract: A Q-switched microlaser is provided that is capable of supporting a zig-zag resonation pattern in response to side pumping of the active gain medium so as to effectively lengthen the microresonator cavity without having to physically lengthen the microresonator cavity. As such, the microlaser can generate pulses having greater pulse widths and correspondingly greater pulse energies and average power levels than the pulses provided by conventional microlasers of a similar size. A corresponding fabrication method is also provided according to one embodiment of the present invention that permits a plurality of side pumped Q-switched microlasers to be fabricated in an efficient and repeatable manner.

Abstract: Ultrasonographic imaging of small calcifications or similar hard bodies distributed in human breast tissue is enhanced by correlating an ultrasonographic data set with a radiographic image of the same region of interest. A “constellation” or cluster of small calcifications is distinguished from speckle noise by the cross-correlation, which is quite sensitive to the coincidence of a pattern of distributed small targets in both the ultrasonographic and radiographic images, notwithstanding the presence of random noise. An optical correlator is preferably used to perform high speed cross-correlations. The three-dimensional position of an individual calcification is preferably found by projecting from an identified point in the radiographic image, along a projection vector, to a voxel with extreme density in the ultrasonographic volumetric data set.

Abstract: The invention is a method and apparatus for adjusting the phase and frequency of a received GPS signal in an inertial-GPS navigation system by inputting a delta-phase at delta-time intervals into the received satellite signal. The method comprises the steps of determining two delta-phase components: (a) a Kalman delta-phase component derived from a plurality of candidate Kalman delta-phase components obtained by performing a first set of more than one Kalman filter processes and (b) an IMU delta-phase component derived from the IMU outputs and a direction-cosine matrix that translates the body coordinates of the IMU into the navigation coordinates of the inertial-GPS navigation system.

Abstract: An optical waveguide network is formed in a substrate of an electrooptically active material. The optical waveguide has input and output facets where optical signals may be input to and output from the integrated optics chip. At least one lateral trench is formed in the substrate. The lateral trench is arranged to prevent light rays incident thereon from inside the substrate from propagating to the output facet. The lateral trench may be formed as a slot that extends toward the surface of the substrate where the optical waveguide network is formed, or the trench may be parallel to the plane of the optical waveguides.

Abstract: The present invention relates to detecting the state of a slide block positioned in a linear valve and using the position of the slide block to predict the health of a linear valve and provide information to a controller/monitor. An operator is provided with information before failure occurrence to allow preventative maintenance of the linear valve. The linear valve is constructed with two canister ports and a vent port. The slide block can be constructed to block the two canister ports and vent port simultaneously. The system can control the position of the block, when provided with position information, hence, using the slide block as a shutoff valve. The typical slide valve can be used as an integral slide shutoff valve, reducing system complexity and reducing system weight, which is critical to airborne applications.

Abstract: The invention is a method and apparatus for compensating for acceleration in a GPS-inertial navigation system. A translated satellite signal is a satellite signal translated in the GPS receiver to an intermediate-frequency band by a sequence of M mixing operations, M being an integer greater than or equal to one. The m'th mixing operation consists of mixing the satellite signal with an m'th mixing signal having a frequency fm where fm can be approximated by a function Fm of one or more components A1, A2, and A3 of the acceleration and one or more parameters Pm1, Pm2, . . . , PmN(m) that are independent of acceleration. The method consists of (a) obtaining values for one or more components of acceleration, (b) obtaining values for one or more parameters, (c)determining the value of one or more functions Fm, and (d) utilizing the data obtained in steps (a), (b), and (c) in compensating for the effects of acceleration in a GPS receiver.

Abstract: Ultrasonographic information about the internal structure of a subject body is combined with x-ray or other radiographic information from the same subject body by using an optical correlator to quickly find a transformation which aligns the information from both sources, even if they are acquired in different coordinate systems. Various spatial transformations are applied to the information and cross-correlations are quickly performed. The transformation which gives the best cross-correlation is used to align the two data sets, which can then be displayed visually. The resulting display can be used as an aid in medical diagnosis, for example in diagnosing suspected malignant lesions in a woman's breast.

Abstract: A method of manufacturing a thin film electrochemical apparatus is disclosed. A near net shape ceramic element is molded including a planar base region and a plurality of tubular regions. The planar base region is infiltrated with a non-conductive material. Each of the tubular regions is infiltrated with a porous conductive material. A porous catalytic electrode material is applied onto the infiltrated regions to form one of a cathodic and anodic surface. A ceramic electrolyte coating is deposited onto the porous catalytic electrode material. A porous catalytic electrode material is applied onto the deposited ceramic electrolyte coating. A porous conductive material is deposited onto the porous catalytic electrode to form the other of the cathodic and anodic surface.

Abstract: A two-dimensional array of Lead-Salt detector elements monolithically formed mounted on an integrated circuit includes an integrated circuit having a passivation layer and a plurality of electrical contacts. The system also includes a delineated, sensitized Lead-Salt layer upon the passivation layer, the delineations forming a plurality of detector elements. The system additionally includes vias through the passivation layer to the electrical contacts and electrical couplers between the electrical contacts and the detector elements.

Abstract: A bi-directional flyback converter (30), as regulated by control circuitry (34), is used to maintain power from a capacitor (36) to aircraft electronics (20) when power from a ground source through bus (12) is switched by a switching relay (16) to the aircraft source through bus (14). When the aircraft is on the ground and prior to engine start up, power is fed through bus (12). Such maintenance of power is necessary during switch-over from the ground to the aircraft power source, to avoid any transitory interruption of power. In operation, once the proper voltage is reached, the circuit turns off, minimizing power consumption. When the input power drops, the bi-directional converter acts as a voltage source, keeping the supply input voltage at a minimum set point by using the energy stored in the capacitor. An anticipation circuit turns on the circuit before power is actually needed so that the response time is instantaneous.

Abstract: A linear amplifier comprises an electron gun assembly having a cathode, and an anode spaced from the cathode. A relatively high voltage potential is applied between the anode and the cathode, and the cathode provides an electron beam in response to the relatively high voltage potential. A control grid is spaced between the cathode and the anode, and is coupled to an input port adapted to receive the input signal. The input signal causes the control grid to density modulate the beam. The control grid is also coupled to a bias voltage source to preclude transmission of the electron beam during the negative half cycle of the input signal. A plurality of collector stages are provided with a respective electric potential thereto ranging between a potential of the cathode and a potential of the anode to efficiently collect the electrons of the beam after passing the anode.

Abstract: A rotation sensor is formed of three semiconductor wafers. A first wafer comprises a frame that surrounds a paddle. The rotation-sensitive paddle is surrounded on either of the opposed sides of the first wafer by rings of driven elements formed of radially-directed plateaus in the semiconductor material. Second and third wafers sandwich the first wafer. Each of the second and third wafers includes a first surface in which are formed concentric rings of driver and pickoff electrodes. In a preferred embodiment, the rings of pickoff electrodes are split into two semicircular arcs.

Abstract: A fiber optic particle motion accelerometer has a housing with a mid-section mounted therein such that the mid-section flexes in response to acceleration along a sensing axis. A proof mass is mounted to an outer edge of the mid-section. A first spiral-wound optical fiber coil is mounted to a first side of the mid-section and a second spiral-wound optical fiber coil is mounted to a second side of the mid-section. A first hinge is formed in the mid-section adjacent the mounting of the mid-section in the housing, and a second hinge is formed in the mid-section between the proof mass and the first and second fiber optic coils. The optical fiber coils are included in an interferometer such that acceleration along the sensing axis produces a phase difference between optical signals propagating in the optical fiber coils.

Abstract: A closed loop accelerometer includes apparatus within an associated digital rebalance loop for reducing the presence of low frequency moding noise in the accelerometer output. In one embodiment, the digitized corrective signal is applied to a moving average filter. In a second embodiment, the corrective signal is modulated with a random function and, in a third embodiment, the digitized corrective signal is both randomized and applied to a moving average filter. In each embodiment, the periodic moding noise that results from the analog-to-digital conversion within the rebalance loop is significantly reduced from that observed in prior art systems.

Abstract: A sensor for measuring rotation rate with respect to three axes and linear acceleration with respect to two axes. Electromagnets comprising cores of high magnetic permeability and windings are fixed to structures that protrude inwardly from outer frames of upper and lower rotor assemblies. An element of high magnetic permeability is fixed to the facing surface of a rotor arm to create electromagnetic drives for counteroscillation of upper and lower sets of rotor arms. Accelerometers are horizontally aligned and fixed to the top surfaces of preselected rotor arms of the upper rotor assembly and to the bottom surfaces of aligned rotor arms of the lower set of rotor arms for measuring rotation rate with respect the x and y axes and linear acceleration with respect to the z axis. The two sets of rotor arms are connected by a torsion bar.

Abstract: A vibratory sensor with a resonator for measuring angular rotation, such as for example a hemispherical resonator gyroscope (HRG) operating in force rebalance mode, includes circuitry to generate a virtual node and antinode in the resonator standing wave. Shifting a pair of pickoff electrodes from a position directly over an actual node in the HRG standing wave to an offset position where the primary and secondary harmonic contributions at the first pickoff electrode are equal to the primary and secondary harmonic contributions at the second pickoff electrode permits the elimination of secondary harmonics contribution. A virtual node is created by offsetting a pair of pickoff electrodes 22.5 degrees from the actual antinode such that each pickoff electrode includes an equal contribution of the secondary harmonic signal present in the standing wave.

Abstract: An image processing system and method visually documents and displays the in-vivo location from which a biopsy specimen was extracted, by processing pre-biopsy and post-biopsy images. A composite image is created which visually emphasizes differences between the pre-biopsy and post-biopsy images. Preferably three-dimensional, digitized images, displayable in various projections, are stored for archival purposes on computer readable media. An image processor preferably exploits an optical correlator to register the pre-biopsy and post-biopsy images accurately. The images are then compared, voxel-by-voxel, to detect differences between pre-biopsy and post-biopsy images. The composite image is displayed with synthetic colors, synthetic icons, or other visual clues to emphasize probable in-vivo biopsy locations.

Abstract: An integrated optics chip includes an optical waveguide network formed on a surface of an electrooptically active material. The optical waveguide network has an input facet where an optical signal may be input to the optical waveguide network and an output facet where optical signals may be output from the optical waveguide network. One or more trenches is formed in the bottom surface of the surface and arranged to extend into the substrate toward the optical waveguide network to a depth of at least 70% of the thickness. The trenches prevent light rays incident thereon from inside the substrate from propagating to the output facet. In particular, the trenches prevent light scattered at the input facet or from scattering centers in the optical waveguide network from reflecting from the bottom surface of the substrate to the output facet. A cover may be mounted to the top surface of the substrate to provide structural strength to the integrated optics chip.