Abstract: A radiation imager includes a photosensor array disposed on a substrate. The photosensor array is optically coupled to a scintillator. A cover plate is disposed over the photosensor array, and the cover plate fully comprises a light absorbing layer interposed between the scintillator and the cover plate.

Abstract: A three-terminal liquid crystal (LC) lens cell includes a center-biased symmetrical quadratic electrode network that has a center electrode electrically coupled to a bias voltage source, and a first and a second network electrode circuit. The respective bias voltage terminus of each network electrode circuit is coupled to the bias voltage source, and the respective control voltage terminus of each network electrode circuit is electrically coupled to a selectively variable lens focus control power supply. Each network electrode circuit further includes respective pluralities of network electrodes electrically coupled together in series and quadratic gradient network biasing resistors respectively electrically coupled therebetween to provide a symmetric quadratic voltage pattern.

Abstract: A programmable liquid crystal optical wavefront device selectively exhibits characteristics either as a lens or as a beam deflector; the device includes a liquid crystal (LC) control apparatus that is disposed in an LC cell to selectively deflect light beams passing through the LC cell. The LC control apparatus includes a bias electrode network and a bias control circuit electrically coupled to the bias electrode network to provide the appropriate bias voltages across the bias electrodes to determine the operation of the device in the lens mode and in the beam deflector mode. The bias control circuit includes a lens bias resistor circuit, a beam deflector bias resistor circuit, each of which comprise a plurality of respective resistor stages, and a lens/beam deflector switch circuit that selectively couples the resistor circuits to the bias electrode network to cause the device to operate in the lens mode or in the beam deflector mode.

Abstract: An interferometric switch for spatially switching either linearly polarized or unpolarized externally derived beams of substantially coherent light includes an optical input unit for dividing an externally derived light beam into a constituent beam pair. An optical phase modulating device includes a nematic liquid crystal pixel for selectively shifting the relative phase of the constituent beam pair. An output unit cooperates to combine respective components of the constituent beam pair along coincident collinear paths so as to form a respective output light beam directed along a selected one of first and second output axes, according to the relative phase imparted by the phase-modulating device. The phase modulating device may comprise a cascading arrangement of pixel stages which can respectively provide a selected incremental phase-shift to each constituent beam passing therethrough.

Abstract: An optical signal processing system includes a number of optical time delay units to generate differentially time-delayed optical signals. Each optical time delay unit includes at least an in put polarizing beam splitter (PBS) system having an input system Thompson prism and an output PBS system including an output Thompson prism. Each Thompson prism has a high extinction ratio and is positioned to act as a polarizing beam splitter, providing a high signal to noise ratio optical signal processing system. Selectively polarized light beams are deflected by the polarizing beam splitters onto predetermined paths that cause the respective light beams to be differentially time delayed dependent on the path that they follow through the optical signal processing system.

Abstract: An interferometric optical switching device for switching substantially coherent light beams includes a plurality of interferometric switching cells arranged in matrix form. Each interferometric switching cell is independently controllable to selectively direct received light beams along at least a selected one of two axes. The device can be three-dimensionally expanded to increase the number of ports to which the light beams can be selectively switched, in which case the matrices can share integrally constructed interferometric switching cells. The device is further capable of providing bidirectional communication between predetermined ones of the ports thereof.

Abstract: An optical switching device for switching arbitrarily polarized optical signal beams includes a plurality of polarization-independent switching cells arranged in matrix form. Each polarization-independent switching cell is independently controllable to selectively direct received optical beams along at least a selected one of two axes. The device can be three-dimensionally expanded to increase the number of output ports to which the optical beams can be selectively switched, in which case the matrices can share integrally constructed polarization-independent switching cells.

Abstract: A compact optical switching unit includes a spatial light modulator coupled to a delay assembly such that incident light beams are respectively selectively directed along either a direct path or a delay path dependent on the linear polarization of the light beam. The delay assembly includes a light deflection device, such as a polarizing beam splitter, coupled to a delay path apparatus, such as mirror prisms or fiber optic cable. A compact and readily fabricated cascade of optical switching units includes polarizing beam splitter blocks and polarization rotation switch blocks, a portion of which constitutes the polarizing beamsplitters and spatial light modulators in respective optical switching units sequentially optically coupled. Delay path apparatuses disposed along an axis orthogonal to both the axis of beams passing along a direct path through polarizing beam splitter switches on the direct path and the axis between respective optical switching units result in a compact optical architecture.

Abstract: A compact optical switching unit includes a polarization independent beamsplitter switch (PIBS) coupled to a delay path apparatus such that incident light beams are respectively selectively directed along either a direct path or a delay path dependent on the the manipulation of the polarization of polarized constituent light beams in the PIBS. The delay path apparatus is typically a mirror prism or fiber optic cable disposed such that light deflected onto the delay path traverses a longer distance than light passing along the direct path and thus a particular light beam can be selectively time delayed by controlling the PIBS to direct the beam into desired delay paths in a cascade of optical signal switching units. A compact and readily fabricated cascade of optical switching units includes PIBS blocks, a portion of which constitutes the PIBS in respective optical switching units sequentially optically coupled.

Abstract: An optical switching device for switching linearly polarized optical signal beams includes a plurality of switching cells arranged in matrix form. Each switching cell has spatial light modulators and a polarizing beamsplitter which cooperate to propagate the optical beams received by the device to selected output ports. The device can be three-dimensionally expanded to increase the number of output ports to which the optical beams can be selectively switched, in which case the matrices can share integrally constructed polarizing beamsplitters and SLMs.

Abstract: A liquid crystal device includes at least one pixel electrode, formed on a transparent substrate, and having opposed first and second sides edges. A transparent cover glass is disposed in parallel alignment with the substrate and has a ground plane formed thereon opposite to the pixel electrode. A multiplicity of liquid crystal molecules is sealably contained between the substrate and cover glass. In one embodiment, a field control electrode (FCE) is formed on the substrate proximate to the pixel electrode first side edge. A voltage of proper polarity and magnitude may be applied to the FCE relative to the ground plane electrode to avoid a disclination line (mobile inversion wall) proximate to the pixel electrode first side edge when another voltage of proper polarity and magnitude is applied to the pixel electrode relative to the ground plane electrode.

Abstract: A novel structural combination for use in gas discharge panels for generating alpha-numeric and video images which exhibit a high level of brightness, even in panels scanned in a point-at-a-time mode and at television scan rates. The combination includes row-wise extending hollow cathodes comprising upper and lower metal cathode plates between which a hollow cathode discharge is generated. The spacing between cathode plates is selected to insure that an efficient hollow cathode discharge is created. Situated forward of the hollow cathodes are a first electrontransmissive grid means for extracting electrons from the hollow cathode dischage, a second electron-transmissive grid means for controlling the flow of electrons through the first and second grid means, and a faceplate having a phosphor coating thereon and adapted to receive an energizing potential for accelerating toward the phosphor coating those electrons which pass through the second grid means.

Abstract: A highly efficient, high current density gas discharge display panel having rows of columns of gas discharge cells. Each row and discharge cells communicates with a row of hollow cathodes formed of row-wise extending front and rear cathode means positioned adjacent and essentially parallel to each other. When a forward and rear cathode means are both energized, they operate together to form a row of hollow cathodes. With only the forward cathode means energized, a low current gas discharge exists in a row of cells, which discharge is transferred to the next adjacent row of cells by the application of scanning signals to the forward cathode means. A simplified unitary center sheet houses the cell enclosures and grooves for anode and cathode conductors to eliminate the need for multiple layers which require registration with one another. The novel structure permits a fast scan rate and efficient priming of the cells to avoid the necessity for high voltage video drivers.

Abstract: A gas discharge display panel and an improved cell therefor. Each cell includes a cathode at one end and a video anode at its other end with a main discharge path between the video anode and the cathode. A priming anode extends along a substantial part of the main discharge path for establishing a priming discharge in the cell which is progressively propagated by the priming anode along the main discharge path toward the video anode. By priming substantially the entire distance between the cathode and the video anode, a low level video signal on the video anode may be used to sustain and control the primed discharge.