Abstract: An optically controlled micro-electromechanical (MEM) switch is described which desirably utilizes photoconductive properties of a semiconductive substrate upon which MEM switches are fabricated. In one embodiment the bias voltage provided for actuation of the switch is altered by illuminating an optoelectric portion of the switch to deactivate the switch. In an alternative embodiment, a photovoltaic device provides voltage to actuate the switch without any bias lines at all. Due to the hysteresis of the electromechanical switching as a function of applied voltage, only modest variation of voltage applied to the switch is necessary to cause the switch to open or close sharply under optical control.

Abstract: Methods for the design and fabrication of micro-electro-mechanical switches are disclosed. Two different switch designs with three different switch fabrication techniques are presented for a total of six switch structures. Each switch has a multiple-layer armature with a suspended biasing electrode and a conducting transmission line affixed to the structural layer of the armature. A conducting dimple is connected to the conducting line to provide a reliable region of contact for the switch. The switch is fabricated using silicon nitride as the armature structural layer and silicon dioxide as the sacrificial layer supporting the armature during fabrication. Hydrofluoric acid is used to remove the silicon dioxide layer with post-processing in a critical point dryer to increase yield.

Abstract: An imaging system that can tolerate high intensity optical beams without a reduction in the system's field-of-view, comprises an imager, a fiber array positioned at the image plane of the imager, a sensor array positioned at the output end of the fiber array, a panel display positioned in proximity of the fiber array and an image processor for electronically processing the information from the sensor array.

Abstract: An opto-electronic accelerometer and pressure sensor formed on a substrate are disclosed. The sensor includes a light source and a plurality of light detectors exposed on a semiconductor substrate. A cantilever beam extends over the substrate. The cantilever beam is positioned such that it reflects light from the light source as an applied force urges the cantilever beam to deflect relative to the plurality of light detectors. Acceleration or pressure can be determined by the slope change of the cantilever beam and is computed by taking the ratio of illumination between corresponding light detectors. In an alternative embodiment, the cantilever beam includes a proof mass. In a further embodiment, a pressure sensor is coupled with a linkage rod which is connected to the cantilever beam and then connected to a diaphragm which is displaced as a pressure is applied.

Abstract: A first surface of a diaphragm is exposed to high temperature gas in the combustion chamber of an internal combustion engine. The curvature of the diaphragm changes in response to the gas pressure. Three optical fibers are spaced along a radius of the diaphragm and have ends which face a second surface of the diaphragm. A light source injects light into a center fiber, which is displaced from the center of the diaphragm by a predetermined distance. Outer fibers receive light from the center fiber after reflection from the diaphragm. The relative intensities of light reflected from the diaphragm into the outer fibers correspond to the curvature of the diaphragm and thereby to the pressure. The outer fibers have a larger numerical aperture than the center fiber, and the light source fully populates all of the optical modes of the center fiber to reduce modal noise caused by physical perturbation of the fibers. The fibers preferably have a square cross-section to maximize linearity.

Abstract: A thermally insulated distributed light network employs an array of discrete, thermally insulative light guides that are spaced slightly away from a central light source and provide optical coupling to optical fibers that have a lower thermal capability. The light guides can either be solid such as quartz, focusing lenses, or a combination of the two. The light receiving ends of the light guides are preferably held by a specially designed coupler so that the guides do not diverge from each other by more than the fibers' optical acceptance angle. The light guides are shaped so that their adjacent edges touch and form an enclosure around the light source, and the fibers are provided in bundles with matching geometries. The network includes an edge-lit display panel that is illuminated by a fiber that has either internal light scattering centers in the form of reflective particles or gas bubbles, or a series of edge notches, to redirect light into the panel.

Abstract: A vehicle lighting system includes one or more central light sources, a plurality of optical loads including headlight lenses, an optical fiber network that extends from the light sources to illuminate the headlight lenses and other optical loads, and optical switches and oscillators that include respective input fibers illuminated from the light source and output fibers to respective optical loads, and operate by enabling and disabling optical connections between their input and output fibers. The headlight assemblies switch between high and low beams by moving their fibers vertically, and control beam diffusion by moving the fibers parallel to the lens axes, including an automatic diffusion adjustment for a headlight reflection from a vehicle in front.

Abstract: A method for fabricating a hybrid MQW spatial light modulator is described which comprises steps of depositing on a substrate in sequence a first layer to preselected thickness of n+ (or p+) semiconductor material, a second layer to preselected thickness of intrinsic semiconductor material and a third layer to preselected thickness of p+ (or n+) semiconductor material to form a modulator portion, applying a metallic layer defining a mirrored surface to the third layer of the modulator portion, providing a prefabricated silicon PIN detector having a layered structure including an intrinsic layer of preselected thickness sandwiched between an n+ layer and p+ layer of respective preselected thicknesses and joining the PIN detector to the mirrored surface using a conductive adhesive layer, selectively boring channels into the modulator portion to preselected depth into the PIN detector to form an array of a plurality of pixels on the modulator portion, filling the channels with light blocking material, and applyi

Abstract: A vehicle lighting system includes one or more central light sources, a plurality of optical loads including headlight lenses, an optical fiber network that extends from the light sources to illuminate the headlight lenses and other optical loads, and optical switches and oscillators that include respective input fibers illuminated from the light source and output fibers to respective optical loads, and operate by enabling and disabling optical connections between their input and output fibers. The headlight assemblies switch between high and low beams by moving their fibers vertically, and control beam diffusion by moving the fibers parallel to the lens axes, including an automatic diffusion adjustment for a headlight reflection from a vehicle in front.

Abstract: An eye protection device 10 comprising a liquid crystal light valve 20 for providing an image of a scene. The light valve images the field of view under observation in a spectral range which matches the human eye. It will automatically reject a laser threat by simply absorbing the energy therefrom in the photoconductive layer thereof. Thus, the invention 10 provides a broad spectrum, zero response time, angle and polarization independent, sensitive eye protection device having a fast recovery time, high extinction coefficient and a high damage threshold. Hence, the invention is expected to be of significant utility to personnel operating in hostile environments.

Abstract: A spatial light modulator includes a photosensor diode and a photoemitting diode array, each having two semiconductive layers of opposite electrical polarities, and which are sandwiched together with layers of the same polarity (P or N) in electrical contact with each other. Transparent electrode layers are formed on the opposite surfaces of the photosensor diode and photoemitting diode array respectively, in electrical contact with the layers of the opposite polarity. The individual photoemitting diodes are electrically and optically isolated from each other. With a voltage applied across the electrodes which causes the photosensor diode to be reverse biased and the photoemitting diodes to be forward biased, the photoemitting diode array generates a visual display which is a reproduction of a light image incident on the photosensor diode. The photosensor diode may be replaced by a single layer of a photoconductive material.