Abstract: A method for manufacturing an electrolytic tilt sensor comprises the steps of: a) forming first and second sensing electrodes on a generally planar surface of a dielectric substrate; b) forming a reference electrode on the generally planar surface; c) mounting a housing to the dielectric substrate so that the first and second sensing electrodes and the reference electrode are contiguous to a volume defined between the housing and the dielectric substrate; d) forming a fluid tight seal between the housing and the dielectric substrate; e) injecting an electrolytic fluid into the volume; f) sealing the electrolytic fluid in the volume; and g) forming an electrical circuit on the dielectric substrate for generating an output signal representing an angular position of the dielectric substrate with respect to a gravitational field.

Abstract: A dynamic range extender for optical transmitters comprises a bipolar distortion compensator for increasing drive signal gain as the absolute level of an input signal increases beyond a selected input voltage threshold, a signal coupler for dividing the input signal into complementary signals, a unipolar distortion compensator for increasing drive signal gain of each complementary signal beyond a selected forward current threshold, a signal clipper for pre-clipping each complementary signal below a selected clipping threshold, and complementary driver outputs to drive each of a pair of laser diodes in a complementary push-pull arrangement. The pre-clipping prevents the laser diodes from being driven below their threshold current level, and the distortion compensation suppresses second and third order harmonic distortion when the complementary signals generated by the laser diodes are combined by differential photodiodes.

Abstract: A continuously variable fiber-optic delay line is created from a deformable polymeric fiber in which lighter density elements, e.g. hydrogen, boron, carbon or oxygen, are diffused through the outer surface of the fiber. The diffusion of the lighter elements creates a non-light transmissive cladding that is of a refractive index that increases from the surface of the fiber towards its axis. The cladding longitudinally surrounds a light transmissive core and has a maximum refractive index that is less than any refractive index of the core. A single-mode, graded-index polymeric fiber is thereby created. By applying a reversible and controllable pressure to the exterior of the deformable fiber, the refractive index of the fiber can be changed accordingly. This change in refractive index permits one to continuously vary the time delay of a signal transmitted through a fixed length of the fiber.

Abstract: A method for fabricating a monolithically integrated liquid crystal array display and control circuitry on a silicon-on-sapphire structure comprises 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 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; and g) fabricating integrated circuitry from the thinned epitaxial silicon layer which is operably coupled to modulate the pixels. The thinned epitaxial silicon supports the fabrication of device quality circuitry which is used to control the operation of the pixels.

Abstract: An active short pulse fuze system for arming on a true target acquisition and firing only on the loss of the acquired target signal. The sea surface is tracked by means of a sea tracking loop A target threshold is established and is coupled to the sea tracking loop so as to expand and contract with the sea tracking. A return signal will pass the target threshold only when there is an abrupt reduction in range, indicating the presence of a target. The presence of this signal will arm the firing circuit. An abrupt increase in range will indicate the loss of the target and cause immediate detonation of the warhead.

Abstract: An ultra-broadband antenna is incorporated into an electrically nonconductive garment. The antenna includes first and second RF elements attached to the garment so that a gap exists between them, where the RF elements each form a band when the garment is worn by a wearer. RF and ground feeds are electrically connected to the first and second RF elements, respectively. A shorting strap electrically connected between the first and second RF elements on the anterior side of the garment generally opposite the feeds helps match the antenna impedance to an external signal source. A gap between the RF elements provides a voltage difference between the RF elements when the antenna is energized. Electrically conductive straps are electrically connected between the anterior and dorsal regions of the first RF element that extend over the shoulder region of the garment.

Abstract: An accelerometer is based upon the monolithic integration of a Fabry-Perot interferometer and a p+n silicon photosensor. Transmission of light through a Fabry-Perot etalon is exponentially sensitive to small displacements in a movable mirror due to an applied accelerating force. The photosensor converts this displacement into an electrical signal as well as provides for additional amplification. Because the interferometer and photosensor are monolithically integrated on a silicon substrate, the combination is compact and has minimal parasitic elements, thereby reducing the accelerometer's noise level and increasing its signal-to-noise ratio (SNR).

Abstract: A detailed sonar target scattering simulation system using object-oriented techniques to implement a broadband computational simulation of a plurality of detailed target highlight features. The class library includes a target class and a highlight base class from which a plurality of highlight subclasses are drawn to accurately represent a wide range of target highlight features. The resulting standard high-level framework allows many operations to be naturally defined and used with reduced software code errors, thereby improving computational effectiveness. The system includes a data processor, a user interface for accepting user commands and data, a display for displaying the simulated acoustic received signal, and a data memory for storing information representing the properties of the acoustic source signal and the positions of the acoustic source signal, the acoustic received signal and the target, and a class library including a target class, a highlight base class and one or more highlight subclasses.

Abstract: A system for alternately directing optical energy through multiple optical modulation channels includes an optical switch having first and second optical output ports for alternately directing an optical signal at full input power out of first and second optical output ports; a first optical modulation channel for modulating the output signal received from the first optical output port; and a second optical modulation channel for modulating the output signal received from the second output port. The optical switch includes a Pockels cell and a birefringent mirror. The Pockels cell transforms a first polarization state of the optical signal into a second polarization state in response to receiving an input signal. The birefringent mirror allows the optical signal to propagate along a first axis when the optical signal has a first polarization state, and directs the optical signal along a second axis when the optical signal has a second polarization state.

Abstract: An improvement to an optical accelerometer based upon the monolithic integration of a Fabry-Perot interferometer and a p+n silicon photosensor includes using one or more pairs of optical accelerometers wherein each pair provides for greater accelerometer sensitivity than a single independent accelerometer, and allows for a reduction in common mode noise due to amplitude and phase difference variations of the utilized light source as well as supply voltage. The differential approach of the invention provides for the biasing of the optical accelerometers such that their output signals are 180 degrees out of phase with each other.

Abstract: A gyroscope is based upon the integration of an optical resonant cavity and a photodiode to detect minute perturbations due to angular forces. A Fabry-Perot cavity is created from two parallel semitransparent mirrors used in conjunction with a monochromatic light source. One mirror is fixed while the other is allowed to rotate with respect to the first mirror. A resonant cavity is thereby formed on either side of the axis. The gap between the mirrors is set so that light transmission through the mirrors is optimized. Rotation of the mirror from this position causes the distance between the mirrors to be altered and the light transmission on either side of the rotational axis to be change. Photodiodes on these sides sense this change as a change in photo-generated current, enabling the amount of change in rotation to be calculated. The photo-currents can be differentially amplified for sensitivity.

Abstract: A novel apparatus is described for a compact solid state dye laser that includes a solid state laser gain element for generating laser pump energy, a passive Q-switch for generating high intensity bursts of laser pump energy, a frequency doubler for generating dye laser pump energy, and a solid state laser dye element for generating optical energy output.

Abstract: A liquid crystal display includes: a) a sapphire substrate having a first crystal lattice structure; b) a single crystal silicon structure having a thickness no greater than about 100 nanometers affixed to the sapphire substrate to create a silicon-on-sapphire structure, and a second crystal lattice structure oriented by the first crystal lattice structure; c) an array of liquid crystal capacitors formed on the silicon-on-sapphire structure; and d) integrated circuitry formed from the silicon layer which is operably coupled to modulate the liquid crystal capacitors. The liquid crystals capacitors may include nematic or ferroelectric liquid crystal material.

Abstract: A microelectromechanical gas concentrator is fabricated for extracting a gaseous component from a gas mixture. The gas concentrator consists of an adsorbent member that alternatively moves between two regions on a single substrate. When the adsorbent member is in the first region, it is allowed to adsorb the gaseous component. When the adsorbent member moves to the second region, it is exposed to radiant energy, causing it to desorb the gaseous component. As the adsorbent member moves alternatively between regions, the gaseous component is adsorbed by the adsorbent member in the first region and desorbed in the second region, resulting in a pumping action that concentrates the gaseous component from one region to the other.

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: 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 three dimensional display provides a true 3-D display of an image defined by luminous voxels within a virtually transparent volume. The voxels may be generated by illuminating a virtually transparent fluorescent gas or dye with beams of excitation energy that cause the gas or dye to emit light at voxels where the energy beams intersect. The voxels may be refreshed in a manner to create either fixed or animated images.

Abstract: A sonar system that includes a new comb-like waveform constructed by modulating the tines of a comb spectrum according to a set of Hermite functions defining a Hermite Function Space (HFS), and a processing method that reduces the sidelobes of the ambiguity function associated with the normally-processed HFS comb waveform. Noise-limited performance remains high, because the waveform is designed to be power-efficient; range ambiguity is superior to the highly-rated sinusoidal frequency-modulation (SFM) waveform; and reverberation-limited performance is equal to or better than that offered by any other waveform designed for this purpose. The full Doppler sensitivity normally associated with pulsed CW can be realized by the application to HFS signals of the constrained, regularized deconvolution method of this invention.