Abstract: An electro-optical modulator and a method for biasing a Mach-Zehnder modulator. The inventive modulator includes a layer of material at least partially transparent to electromagnetic energy. A first conductive layer is disposed on a first surface of the layer of at least partially transparent material. A second conductive layer is disposed on a second surface of the layer of at least partially transparent material. A layer of insulating material is disposed on the second conductive layer and a third conductive layer is disposed on the layer of insulating material. In the illustrative application, the modulator is a Mach-Zehnder modulator. A biasing potential is applied to the second conductive layer of the modulator and a modulating voltage is applied across the first and the third conductive layers.

Abstract: An electro-optical modulator and a method for biasing a Mach-Zehnder modulator. The inventive modulator includes a layer of material at least partially transparent to electro-magnetic energy. A first conductive layer is disposed on a first surface of the layer of at least partially transparent material. A second conductive layer is disposed on a second surface of the layer of at least partially transparent material. A layer of insulating material is disposed on the second conductive layer and a third conductive layer is disposed on the layer of insulating material. In the illustrative application, the modulator is a Mach-Zehnder modulator. A biasing potential is applied to the second conductive layer of the modulator and a modulating voltage is applied across the first and the third conductive layers.

Abstract: A method and apparatus for protecting a bolometer antenna imaging array from out of band electromagnetic energy is disclosed. Protective pads are disposed upon a window in an optical system forming a millimeter wave image on an array of bolometer antenna sensors. The protective pads are effectively opaque to infrared and visible emissions and are aligned to shade the bolometer portion of the bolometer antennas from infrared and visible emissions, while leaving the antenna portion of each sensor in the array exposed to intercept the millimeter wave energy incident upon them.

Abstract: The system (10) includes a first mechanism (12) for receiving electromagnetic energy of a first wavelength from the scene (28) and providing electromagnetic energy of a second wavelength shorter than the first wavelength. A second mechanism (14) measures variations of the electromagnetic energy of the second wavelength over a predetermined area. The system is a millimeter wave imaging system (10). The first mechanism (12) includes a lens (12) having an index of refraction substantially greater than 1. The lens (12) is opaque to infrared electromagnetic energy and made of alumina, plastic, or other material having a relatively high index of refraction. The second mechanism (24) includes and array of bolometers (24) positioned parallel to an output aperture (24) of the lens and within a distance of the output aperture (24) that is much smaller than the second wavelength.

Abstract: An integrated infrared and millimeter-wave monolithic focal plane sensor array having a substrate upon which an integrated array of infrared sensors and mm-wave sensors are provided at a first planar level on the same side of the substrate, and a planar antenna for receiving incident millimeter-wave radiation located at a second planar level located between the integrated array of sensors and the surface of the substrates for coupling the mm-wave radiation field to the mm-wave sensor. The antenna receiver of electromagnetic radiation, in one embodiment, is an antenna having a crossed bowtie configuration which efficiently couples the radiation field to the mm-wave sensor. The invention also is directed to a method of fabricating such a radiation sensor.

Abstract: A radiation sensor. The inventive sensor has a two-level detector structure formed on a substrate in which a thermal detector element is suspended over the substrate as a microbridge structure. A receiver of electromagnetic radiation is provided on the same side of the substrate in a manner that efficiently couples the radiation field to the thermal detector element. The thermal detector element has a sandwich structure including a heater metal layer, a dielectric layer, and a thin film thermo-resistive material. The thermal detector element is suspended out of physical contact with the receiver. In one embodiment, the receiver is an antenna having a crossed bowtie configuration that efficiently couples the radiation field to the detector element. The inventive radiation sensors are especially useful for mm-wave and microwave sensing applications. The sensor can be used individually or in linear or two-dimensional arrays thereof.

Abstract: A low profile receiving and/or transmitting antenna includes an array of lenses that focuses millimeter wave or other radiation onto a plurality of conventional patch antenna elements. The lenses and antenna elements are physically configured so that radiation at a tuning wavelength impinging on the antenna at a particular angle of incidence is collected by the lenses and focused onto the antenna elements in-phase. Two rotatable prisms may be disposed above the lenses to alter the angle of incidence of incoming or outgoing radiation to match the particular angle of incidence.

Abstract: A holographic optical filter separates broadband electromagnetic radiation into spectral components corresponding to different spectral regions and then images this radiation onto pixels of a display. It includes two layers of holographic optical elements that are sensitive to each of these spectral regions. The holographic optical elements generally transmit radiation outside of their bandpass but can diffract radiation falling within it. The filter is well suited for display applications and can be used in either a reflective or transmissive mode.

Abstract: The angular and/or spectral bandwidth of a holographic lens assembly can be widened to accomodate highly diverging and/or wide spectral bandwidth illumination sources, respectively. Each lens in the lens assembly is comprised of a plurality of angularly customized holograms (an angularly customized hologram set). Each of the individual holograms in an angularly customized hologram set has an acceptance angle range that is centered on a discrete peak acceptance angle. The separation between the holograms' peak acceptance angles is chosen so that the acceptance angle ranges of the individual holograms overlap. The resulting cumulative acceptance angle range of each angularly customized hologram set provides a holographic lens assembly that has a wider angular bandwidth than prior holographic lenses.

Abstract: A compact scanned antenna which includes a radiator, a rotatable tube and a line source. The radiator is formed by plating a shaped dielectric core. It generates an antenna beam at an output aperture in response to a microwave signal at an input port. The line source generates a radiation sheet which is directed across a signal plane to the input pot. The tube has a cylindrical wall which is positioned across the signal plane. As the tube rotates, refractive or diffractive transmission structures pass through the signal plane. The refractive structures include linear segments which refract the wavefront of the radiation sheet. Because the wavefront slope at the radiator's aperture is a function of the wavefront slope at its input port, the antenna beam is scanned. The linear contour segments have the same inclination but are not colinear. This arrangement reduces the thickness of the tube wall. Phase coherence is achieved by an appropriate radial spacing of adjacent ends of contour segments.

Abstract: An infrared (IR) radiation transducer integrates an IR detector array with a liquid crystal (LC) readout. The IR detector is preferably a pixelized bolometer array, but other detectors such as pyroelectric materials are possible. To modulate the LC in response to detected IR radiation, a modulating section is provided that includes a charge injection structure which injects electrical charge in response to the detected IR radiation, and a charge transfer structure that transfers the injected charge to the LC readout section. During its active phase the charge transfer layer is depleted of majority charge carriers, and the charge injection and transfer mechanism operates in a manner analogous to a bipolar transistor. A visible readout is obtained by directing readout light through the LC, where it is modulated in accordance with the detected IR image. The transducers are small and light weight enough to be incorporated into a pair of goggles, for which no separate cooling is required.

Abstract: An optical beam scanner incorporating an array of beam deflection elements commonly controlled to steer an optical beam impingent on the array is described. The beam steering elements are arranged in the array as individually controlled elements and the deflection of the beam is accomplished by setting the phase tilt and the phase offset of each element according to a calculation which removes modulo 2.pi. phase shift from the required position relative to a flat plane. Thus, the array elements can be thin and need only supply about 2 radians of phase shift. These elements may be incorporated in a planar array using beam deflection elements such as liquid crystal beam deflectors by choosing a drive scheme representing either a blazed array or a flat piston array.

Abstract: An integrated circuit structure and method of forming the same is described in which a plurality of common signal planes are provided for an integrated circuit formed on a layer of semiconductive material (30). The common planes consist of a single crystal semiconductive substrate (2) and at least one conductive layer (26, 66) between the substrate (2) and the semiconductive circuit layer (30), with insulative layers (24, 28, 68) separating the conductive layers (26, 66) from each other and from the substrate (2) and semiconductive layer (30). When one conductive layer (26) is used, a power supply signal (V+) is preferably applied to the substrate (2) and a ground reference to the conductive layer (26). Contacts are made between the integrated circuit and the desired common planes by metallized contacts (56, 60) formed in openings (54, 58) through the underlying material. Various circuit signals can also be introduced through additional conductive layers.

Abstract: A 3-D IC chip assembly is formed from stacked substrates in which each individual substrate has a plurality of different IC chips retained in respective recesses. Conductive feedthroughs extend through the substrate from the side where the chips are located to the opposite side, with the chips electrically connected to the feedthroughs. An electrical routing network on the opposite side of the substrate from the chips provides desired interconnections between the chips by connecting to the feedthroughs. The routing can be formed by standard photolithographic techniques.

Abstract: An infrared (IR) simulator is disclosed in which an array of pixels is defined on an insulative substrate by resistor bridges which contact the substrate at spaced locations and are separated from the substrate, and thereby thermally insulated therefrom, between the contact locations. Semiconductor drive circuits on the substrate enable desired current flows through the resistor bridges in response to input control signals, thereby establishing the appropriate IR radiation from each of the pixels. The drive circuits and also at least some of the electrical lead lines are preferably located under the resistor bridges. A thermal reflector below each bridge shields the drive circuit and reflects radiation to enhance the IR output. The drive circuits employ sample and hold circuits which produce a substantially flicker-free operation, with the resistor bridges being impedance matched with their respective drive circuits.

Abstract: An integrated circuit structure and method of forming the same is described in which a plurality of common signal planes are provided for an integrated circuit formed on a layer of semiconductive material (30). The common planes consist of a single crystal semiconductive substrate (2) and at least one conductive layer (26, 66) between the substrate (2) and the semiconductive circuit layer (30), with insulative layers (24, 28, 68) separating the conductive layers (26, 66) from each other and from the substrate (2) and semiconductive layer (30). When one conductive layer (26) is used, a power supply signal (V+) is preferably applied to the substrate (2) and a ground reference to the conductive layer (26). Contacts are made between the integrated circuit and the desired common planes by metallized contacts (56, 60) formed in openings (54, 58) through the underlying material. Various circuit signals can also be introduced through additional conductive layers.

Abstract: An adaptive optics system is disclosed which has a phase detector to detect phase distortions acquired by an input beam, and a separate phase adjustor which predistorts a transmission beam so that it is restored to its proper phase during transmission back through the same medium travelled by the input beam. The phase adjustor consists of a liquid crystal mechanism with an area substantially greater than that of the phase detector, thereby permitting high power operation. Liquid crystal pixels in the phase adjustor have dual transistor signal storage circuits which apply operating signals to the pixels without significant decay or flicker. The phase adjustor can be constructed in either a reflective or transmissive mode. Two phase adjustors may be placed in series to enhance response time and/or process an unpolarized beam. A data processor interfaces between the phase detector and phase adjustor.

Abstract: An optical beam scanner incorporating an array of beam deflection elements commonly controlled to steer an optical beam impingent on the array is described. The beam steering elements are arranged in the array as individually controlled elements and the deflection of the beam is accomplished by setting the phase tilt and the phase offset of each element according to a calculation which removes modulo 2.pi. phase shift from the required position relative to a flat plane. Thus, the array elements can be thin and need only supply about 2 radians of phase shift. These elements may be incorporated in a planar array using beam deflection elements such as liquid crystal beam deflectors by choosing a drive scheme representing either a blazed array or a flat piston array.

Abstract: A cellular array processor (10) for efficiently performing data dependent processing such as floating point arithmetic functions. One module (84) in the array processor (12) generates a signal applied to bus line (24) when all of the bits in a register (86) are zero. The signal on bus line (24) effects the shifting operation of a shift register (36) in a memory module (34) located on a different functional plane. Thus, the processing functions carried out in each elemental processor (26) can be made to depend on the value of data stored therein instead of being dictated solely by a simultaneous executed instruction from the control processor (14) as is the normal case.

Abstract: A single-Schottky liquid crystal is disclosed in which a series of Schottky contacts are made on one side of a photoconductor substrate by a metal matrix mirror, with a doped semiconductor back contact electrode on the other side of the substrate. The light valve offers several operational advantages over MOS devices, and is easier to fabricate than double-Schottky light valves. It can be operated either in an AC mode or, by doping the liquid crystal ions, in a DC mode.