Abstract: A 3D ultraviolet (UV) imaging LADAR system includes a UV source configured to generate a UV interrogation beam, a sensor configured to receive a UV return beam reflected from a target and to produce an electrical signal, and an imaging module coupled to the sensor and configured to receive the electrical signal and to generate a corresponding 3D image of the target. In one example, the sensor includes a down-shifting device configured to down-shift the UV return beam to a down-shifted light beam of a different wavelength, for example, in the visible or SWIR wavelength ranges.

Abstract: A 3D ultraviolet (UV) imaging LADAR system includes a UV source configured to generate a UV interrogation beam, a sensor configured to receive a UV return beam reflected from a target and to produce an electrical signal, and an imaging module coupled to the sensor and configured to receive the electrical signal and to generate a corresponding 3D image of the target. In one example, the sensor includes a down-shifting device configured to down-shift the UV return beam to a down-shifted light beam of a different wavelength, for example, in the visible or SWIR wavelength ranges.

Abstract: In one exemplary embodiment, a detector of electromagnetic radiation includes: a substrate; at least one layer of semiconductor material formed on the substrate, said at least one layer of semiconductor material defining a radiation absorbing and detecting region; an electrical contact configured to couple said region to a readout circuit; and a fuse coupled between the region and the electrical contact. In another exemplary embodiment, a fusible link between a first component and a second component is provided and includes: a fuse with an undercut located underneath at least a portion of the fuse; a first contact coupling the first component to the fuse; and a second contact coupling the second component to the fuse, wherein the undercut is disposed between the first contact and the second contact. In another exemplary embodiment, a fusible link includes a fuse having a layer of material having a negative temperature coefficient of resistance.

Abstract: A radiation sensor (20) has a substrate (34); an antenna (24) coupled to the substrate (34), a thermal detector unit TDU (22) spaced from the antenna (24) and the substrate (34); and a multi-layered conductive lead (30). The conductive lead (30) physically contacts the antenna (24) and the TDU (22). The conductive lead (30) defines a support layer (44) adjacent to the substrate (34) for structurally supporting the TDU (22) over a cavity defined by the substrate (34), a buffer layer (46) disposed on the support layer (44), and a superconductive layer (48) disposed on the buffer layer (46). The buffer layer has a crystalline structure to facilitate bonding with other layers. A method for making the sensor (20) is disclosed wherein the superconductive layer (48) and the buffer layer (46) are deposited using laser deposit, the buffer layer (46) with ion beam assist for alignment.

Abstract: A radiation sensor (20) has a substrate (34); an antenna (24) coupled to the substrate (34), a thermal detector unit TDU (22) spaced from the antenna (24) and the substrate (34); and a multi-layered conductive lead (30). The conductive lead (30) physically contacts the antenna (24) and the TDU (22). The conductive lead (30) defines a support layer (44) adjacent to the substrate (34) for structurally supporting the TDU (22) over a cavity defined by the substrate (34), a buffer layer (46) disposed on the support layer (44), and a superconductive layer (48) disposed on the buffer layer (46). The buffer layer has a crystalline structure to facilitate bonding with other layers. A method for making the sensor (20) is disclosed wherein the superconductive layer (48) and the buffer layer (46) are deposited using laser deposit, the buffer layer (46) with ion beam assist for alignment.

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: 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: An integrated dual sensor package comprises a housing, a first sensor assembly and a second sensor assembly. The housing includes an internal vacuum chamber, a first window and a second window. The first window is transparent to a first wavelength of propagating energy and the second window is transparent to a second wavelength of propagating energy. The first sensor assembly and the second sensor assembly each have an active region responsive to a respective one of the first wavelength and second wavelength of propagating energy. The first sensor assembly and the second sensor assembly are each mounted within the vacuum chamber with the active region of each of the first sensor assembly and the second sensor assembly adjacently aligned with a respective one of said first window and said second window. The common alignment structure also serves as a common thermal interface to the external environment.

Abstract: A microbolometer detector element (10) for a focal plane array is provided including an optically absorptive material structure (12) characterized by an electrical resistivity that varies as a function of its temperature coupled in spaced relation to a thermal isolation structure (20). The thermal isolation structure (20) is coupled in spaced relation to a sensor (34) connected to the optically absorptive material structure (12) for sensing the absorptive structure's (12) electrical resistivity. The thermal isolation structure (20) facilitates very high fill factors even when the pixel size is shrunk below the baseline fifty micron size. The thickness of the optically absorptive material structure (12) and the thermal isolation structure (20) can be independently controlled since the thermal isolation structure (20) is disposed in spaced relation under the absorptive material structure (12).

Abstract: A method and apparatus for sensing a composition of an exhaust plume includes a light source that radiates an infrared light beam having a plurality of predetermined wavelengths. A first of the predetermined wavelengths is associated with carbon dioxide and a second of the predetermined wavelengths is associated with a second gas, such as a hydrocarbon or carbon monoxide. The apparatus also includes a detector unit that detects the beam passing through the plume. The apparatus computes a ratio of the second gas to carbon dioxide based upon the first and second detected wavelengths, and this ratio is then multiplied by a predetermined estimation of a concentration of carbon dioxide in the plume.

Abstract: An imaging device (10, 10') has a plurality of unit cells (11) that contribute to forming an image of a scene. The imaging device includes a layer of wide bandgap semiconductor (18) material (e.g., silicon) having photogate charge-mode readout circuitry (20, 22, 24), such as CCD or CMOS circuitry, disposed upon a first surface of the layer. In one embodiment a second, opposing surface of the layer is bonded at a heterojunction interface or atomic bonding layer (16) to a surface of a layer of narrower bandgap semiconductor material (e.g., InGaAs or HgCdTe), that is selected for absorbing electromagnetic radiation having wavelengths longer than about one micrometer (i.e., the NIR or longer) and for generating charge carriers. The generated charge carriers are transported across the heterojunction interface for collection by the photogate charge-mode readout circuitry.

Abstract: An imaging device (10) has a plurality of unit cells that contribute to forming an image of a scene. The imaging device includes a layer of semiconductor material (16), for example silicon, that has low noise photogate charge-mode readout circuitry (20, 21, 26, 28) (e.g., CCD or CMOS readout circuitry and structures) that is disposed upon a first surface (18) of the layer. A second, opposing surface of the layer is a radiation admitting surface of the layer. The layer has a bandgap selected for absorbing electromagnetic radiation having wavelengths shorter than about one micrometer and for generating charge carriers from the absorbed radiation. The generated charge carriers are collected by the photogate charge-mode readout circuitry. A thermal sensing element (22) is disposed above and is thermally isolated from the first surface of the layer. The thermal sensing element may be, by example, one of a bolometer element, a pyroelectric element, or a thermopile element.

Abstract: A system (10) for simultaneously measuring temperature and CO, CO.sub.2 and HC gas content of vehicle (11) exhaust detects and analyzes a beam of infrared electromagnetic radiation (21) projected through a plume (13) of vehicle exhaust to assess the concentration of CO, CO.sub.2, and HC in the vehicle exhaust and detects and analyzes infrared electromagnetic radiation (15) emitted by the plume (13) to assess the temperature of the plume (13) and, consequently, whether the vehicle's (11) catalytic converter is operating in the cold or hot mode. Essentially simultaneous measurement is taken by intermittently interrupting the beam (21) of projected infrared electromagnetic radiation and detecting and analyzing the emitted infrared radiation (15) during the intervals of interruption when the beam (21) is not projected through the plume (13). Intermittent projection of the beam (21) is accomplished by insertion of a chopper wheel (22) between an infrared beam projector (20) and the plume (13).

Abstract: An unmanned integrated RES 12 integrates all of its components except the reflector 22 into a single console 30 that is positioned at the side of a road and has a CPU 36 that controls calibration, verification and data gathering. The RES's source 32 and receiver 34 are preferably stacked one on top of the other such that the IR beam 24 traverses a low and high path as it crosses the road 14. This allows the RES to detect both low and high ground clearance vehicles. To maintain the vehicle processing and identification throughput, the speed sensor 54 and ALPR 48,50 detect the passing vehicles at steep angles, approximately 20 to 35 degrees. In a preferred system, a manned control center 16 communicates with a large number of the unmanned integrated RES to download emissions data, perform remote diagnostics, and, if necessary, dispatch a technician to perform maintenance on a particular RES.

Abstract: An emission-concentration monitoring system (20)includes first and second monitor stations (22,32) which are separated by a sensing space (40) along a path (28) of a moving vehicle (26). Each station has a source of electromagnetic radiation (64) which is directed through the vehicle's exhaust plume. Each station also has a set of detectors (66) which are positioned to receive the radiation and configured to measure transmittances at wavelengths which are absorbed by molecular species of exhaust plume (e.g., hydrocarbons, nitric oxide, carbon monoxide and carbon dioxide). These sensed transmittances are converted to emission concentrations by a data processor (50) and compared to a set of emission-concentration standards. The vehicle is determined to be in violation only if its emission concentrations at both the first and second monitor stations exceeds the standards.

Abstract: A highly integrated thermal sensor (10) is responsive to radiation having wavelengths within a predetermined band of wavelengths. The sensor, which may be a thermopile, is comprised of a substrate (16) comprised of at least one semiconductor material. The substrate includes at least one active region disposed within a first surface of the substrate. The sensor further includes a plurality of thermally-responsive junctions (HJ, CJ) between dissimilar materials (22, 24) that are disposed within the at least one active region, wherein at least one of the thermally-responsive junctions is a hot junction. The hot junction is thermally isolated from the substrate by being suspended from the substrate on dielectric bridges or, in another embodiment, by a thermally insulating and patterned polymer. In a backside illuminated embodiment of this invention the sensor further includes an optical cavity (26) formed within a second surface of the substrate in registration with the active region.

Abstract: A light source radiates an infrared beam that passes through a chopper, a calibration cell and the exhaust plume of a motor vehicle passing in front of the source. A photosensor assembly includes a plurality of photodetectors which are spaced closely adjacent to each other and simultaneously sense the beam after it propagates through the plume. An optical beam homogenizer or integrator disposed between the plume and the photosensor unit causes the light incident on the photodetectors to have uniform intensity. The photodetectors are sensitive to different wavelengths corresponding to spectral absorption peaks of constituents of the composition of the plume, including carbon monoxide (CO), carbon dioxide (CO.sub.2), hydrocarbon (HC), water vapor (H.sub.2 O) and nitric oxide (NO). A computer computes the composition of the plume as the percentages of the constituents based on the sensed transmittances of the respective wavelengths through the plume.

Abstract: An unmanned integrated RES 12 integrates all of its components except the reflector 22 into a single console 30 that is positioned at the side of a road and has a CPU 36 that controls calibration, verification and data gathering. The RES's source 32 and receiver 34 are preferably stacked one on top of the other such that the IR beam 24 traverses a low and high path as it crosses the road 14. This allows the RES to detect both low and high ground clearance vehicles. To maintain the vehicle processing and identification throughput, the speed sensor 54 and ALPR 48,50 detect the passing vehicles at steep angles, approximately 20 to 35 degrees. In a preferred system, a manned control center 16 communicates with a large number of the unmanned integrated RES to download emissions data, perform remote diagnostics, and, if necessary, dispatch a technician to perform maintenance on a particular RES.

Abstract: An unmanned integrated RES 12 integrates all of its components except the reflector 22 into a single console 30 that is positioned at the side of a road and has a CPU 36 that controls calibration, verification and data gathering. The RES's source 32 and receiver 34 are preferably stacked one on top of the other such that the IR beam 24 traverses a low and high path as it crosses the road 14. This allows the RES to detect both low and high ground clearance vehicles. To maintain the vehicle processing and identification throughput, the speed sensor 54 and ALPR 48,50 detect the passing vehicles at steep angles, approximately 20 to 35 degrees. In a preferred system, a manned control center 16 communicates with a large number of the unmanned integrated RES to download emissions data, perform remote diagnostics, and, if necessary, dispatch a technician to perform maintenance on a particular RES.