Abstract: An anti-reflective structure is formed on a surface to transmit incident light with minimal losses. The anti-reflective surface has a plurality of protrusions having a feature size smaller than the wavelength of incident light. The protrusions increase in height in either a sloped linear manner or in a curvilinear manner, and the protrusions repeat across the surface in at least one dimension to transmit the incident light. Gray scale lithography may be used to produce these patterns of protrusions in photoresist layers. High fidelity transfer of the protrusion patterns into the surfaces is accomplished by utilizing, for example, an electron cyclotron resonance plasma. Transmission values at such patterned surfaces maybe as high as 99.3%.

Abstract: A system and an apparatus for matching infrared radiation emitted from aircraft skins to background infrared radiation in order to minimize the contrast between the two radiations, and to thereby camouflage the aircraft from electro-optical detection systems. In particular, there are employed heat pipe systems and apparatus for cooling the internal surface of an aircraft skin, and especially the bottom portion of an airframe, for the camouflage of the aircraft from the look-up viewing aspect angles of electro-optical detection systems by transferring heat otherwise emitted by the skin to the fuel which is carried by the aircraft.

Abstract: An infrared radiation (IR) detector device that comprises a casing, having an optical window for admitting radiation; a cold shield having a detector mounted therein and having a filter mounted between the optical window and the detector; a cooler tube in coiled configuration, having an inlet in communication with a pressurized gas source and an expansion nozzle located in the vicinity of the detector and a pre-cooling jacket, enclosing the cooler tube and having a gas inlet in the vicinity of the detector and a gas discharge vent to the outside. The cooler tube comprises a first section, beginning at the gas inlet, a second section, terminating at the expansion nozzle, and a communication between the first and second sections. The pre-cooling jacket comprises a first section, housing the first section of the cooler tube, a second section, housing the second section of the cooler tube, and a communication between the first and second sections.

Abstract: A sensor/support system includes a sensor assembly having a planar radiation detector lying parallel to a reference plane, a readout circuit, and an interconnect joining the radiation detector to the readout circuit. The system further includes a support structure, the support structure having a platform with a first side to which the sensor assembly is affixed and a second side oppositely disposed from the first side. A shim is affixed to the second side of the platform. The shim is made of a shim material different from the detector material and the platform material. The shim reduces the strain in the interconnect when the temperature of the sensor/support system is changed, as compared with the strain in the interconnect in the absence of the stabilization structure.

Abstract: An infrared spectrometer is adapted to capture spectral data at high frequency and includes an aperture defining slit and tuning fork chopper for periodically admitting infrared radiation. A lens and a plurality of mirrors direct the infrared radiation through pair of calcium fluoride prisms that split the infrared radiation into spectral components. The spectral components are directed by an additional mirror and lens to an array of lead selenide pixels that generate a set of data indicative of the spectral component intensities. Data collection circuitry coupled to the pixel array and coupled to the tuning fork chopper collects the set of data at a selectable rate at least once during each opening of the aperture. A serial output on the data collection circuitry provides a list of data values representative of the spectral intensity at each pixel which can be then stored in a mass storage device as well as immediately analyzed based on selected criteria.

Abstract: This invention consists of a bias and readout scheme for resistive bolometers. It is chiefly intended for use with bolometer materials which exhibit a phase transition that is hysteretic. A preferred bolometer material is vanadium dioxide, which has a metal-semiconductor phase transition at 68° C. and a hysteresis of typically 5° C., depending on material preparation. The existence of hysteresis precludes the use of a conventional dc bias or a conventional pulsed bias in a bolometer operated on the phase transition. In the present method, the bias consists of an ac current for phase transitions in which the resistance decreases with increasing temperature. For phase transitions in which the resistance increases with temperature, an ac voltage bias would be used.

Abstract: A device for controlling equipment includes a light projector adapted to project light onto a head of a living body, a light collecting device for collecting the light having passed through the head from the light projector, a light measuring device for measuring an intensity of the light collected by the light collecting device, a memory device for storing a previous history of changes of the intensity of the light measured by the light measuring device, a signal judging circuit for judging if both the intensity of the light measured by the light measuring device and the previous history of changes of the intensity of the light satisfy a predetermined condition, a display device for displaying the intensity of the light measured by the light measuring device and a result obtained by the signal judging circuit, and a control signal generating circuit for generating a control signal to be supplied to an external equipment if the predetermined condition is satisfied.

Abstract: A method and apparatus for correction of temperature-induced variations in the analog output characteristics of a microbolometer detector in an infrared detecting focal plane array utilizing electronic means to correct for the temperature variation of the individual microbolometer detector. The electronic circuitry and associated software necessary for implementation is also described.

Abstract: An uncooled infrared imager and associated microelectromechanical infrared detectors based on an active pixel heat balancing technique are disclosed. The imager is fabricated using a commercial CMOS process plus a simple electrochemical etch stop releasing step. The basic active pixel detector structure consists of a simple cascode CMOS amplifier in which the PMOS devices are built inside a thermally-isolated floating n-well. The intrinsic coupling of the cascode currents with the self-heating of the well forms an electrothermal feedback loop that tends to maintain the well temperature constant. By employing the heat balance between incoming infrared radiation and the PMOS device power dissipation, the responsivity of the detector is controlled by the cascode biasing current.

Abstract: Presented is a sensor system for the detection of thermal radiation, with a substrate (15) and several sensor elements (10) on the substrate (15), in which case at least one self-test device (53) is provided in order to generate heat which can be used for the heating of one or more sensor elements (10). The sensor elements (10) can be heated according to a typical time pattern during the self-testing process. Also presented is an advantageous process for the manufacture of the sensor system as well as an advantageous configuration of the total system, including signal processing.

Abstract: This invention provides an EDS detector in which even if connecting pipes vibrate due to gas flow, such vibration will not be transferred to a cryostat side and in which a small-sized gas-circulation-type refrigerator is provided in the cryostat sliding in a given direction, helium gas is supplied through the connecting pipes to the refrigerator, and an x-ray detecting element is cooled by means of the refrigerator. In connecting pipes, a connecting pipe body portion is connected to a pressure-converting value unit which is fixedly held in a vibration-proofing stand. Additionally, weights can be selectively applied to a flexible connecting pipe to further dampen vibrations.

Abstract: An infrared imaging device including a quantum device positioned and configured to detect infrared transmission at ambient temperature, a cooler thermally coupled to the quantum device, and controller for controlling the cooler based on a function of plural image-taking parameters as a command.

Abstract: A semiconductor nanocrystal compound is described which is capable of linking to one or more affinity molecules. The compound comprises (1) one or more semiconductor nanocrystals capable of, in response to exposure to a first energy, providing a second energy, and (2) one or more linking agents, having a first portion linked to the one or more semiconductor nanocrystals and a second portion capable of linking to one or more affinity molecules. One or more of these semiconductor nanocrystal compounds are linked to one or more affinity molecules to form a semiconductor nanocrystal probe capable of bonding with one or more detectable substances in a material being analyzed, and capable of, in response to exposure to a first energy, providing a second energy.

Abstract: An infra-red radiation detector having a Dewar type vessel is provided with a coupler which is coupled to the wall of the vessel. The coupler includes a fiber which can transmit infra red radiation and which terminates close to a detector provided in the Dewar type vessel. No special optical arrangement is required in order to couple an external fiber to the detector and the arrangement is inherently aligned.

Abstract: An infrared image is directed onto a transducer having a planar array of absorbing discs, on one side. The discs are supported by a thin membrane which sags or bulges as the discs heat up. The discs thus change their spacings with respect to a partially reflective mirror. The nominal spacing between the discs and mirror is about ¼ wave-length of the infrared radiation, such that absorption is enhanced. The mirror is supported on a transparent substrate through which visible or near-infrared radiation is shown; the mirror/discs thus establish a Fabry-Perot cavity for this radiation, whereby a visible or near-infrared image may be observed or detected as the various discs establish various spacings in accordance with incremental variations in the infrared image. An alternate embodiment uses an electrostatic field to pre-bias the discs toward the mirror and thus to tune or adjuct the sensitivity of the transducer.

Abstract: A two-dimensional photonic radiation detector based on a technique of hybridizing a detection chip onto a read chip through a micro-balls network making the electrical and mechanical inter-connection between two chips, the detection chip being composed of a two-dimensional structure of ixj pixels, an active layer (41) being epitaxed onto a substrate (40), each elementary photosensitive component consisting of an N/P or P/N diode formed in the active layer (41), the contact point on the N or P area being made at each pixel, the contact point on the other P or N area being common to all diodes, in which the detector includes a wide gap optically and electrically transparent intermediate layer (42) located between the active layer (41) and the substrate (40).

Abstract: A light weight decoy for deceiving radar and forward looking infrared tracking systems. The decoy provides the same radar cross-section as that of an intercontinental ballistic missile (ICBM) and is thermally massive across the entire black body spectrum. Thermal massiveness is accomplished by measuring the temperature of the decoy outer surface and the temperature of the space surrounding the decoy, obtaining the differential temperature, and radiating heat within the decoy to maintain the surface thereof at a temperature similar to that of an ICBM.

Abstract: A radiation detecting apparatus comprises a container having a vacuum space, a radiation detecting element disposed in the vacuum space for detecting radiation, and a cooling element disposed in the container for cooling the radiation detecting element to a preselected cooling temperature during operation of the radiation detecting apparatus. A physical absorbing material is disposed in the container for absorbing gases from the vacuum space. A chemical absorbing material capable of activation by heat is disposed in the container for absorbing gases from the vacuum space. A heating device is provided for heating the chemical absorbing material. A measurement and control circuit measures a temperature of the radiation detecting element or a degree of vacuum in the vacuum space to determine whether or not the chemical absorbing material should be activated by the heating device.

Abstract: An infrared video camera system comprises an uncooled infrared sensor mounted and a thermally conductive thin walled radiation shield for shielding radiation from reaching an active surface of the uncooled infrared sensor. A TEC maintains the sensor active surface and the radiation shield at a substantially constant temperature. The uncooled infrared sensor and radiation shield are further housed in a hollow thermally conductive vacuum cover which is vacuum sealed with a base assembly and includes a vacuum sealed infrared transparent window in an aperture at a top end of the vacuum cover for allowing infrared radiation to reach the active surface and for forming a vacuum chamber enclosing the infrared sensor and radiation shield. A relay optical cell mounted to a camera body comprises at least one optical element for relaying an image formed at its entrance onto the active surface.

Abstract: A thermal infrared camera includes a thermal infrared image pickup element with a plurality of light-receiving parts generating heat in response to incident infrared radiation. The incident infrared radiation is detected using changes in electrical characteristics of each of the plurality of light-receiving parts, an image-focusing optical system used for image pickup, and a temperature-controlled infrared radiation blocking body that has an opening for conducting infrared radiation from the image-focusing optical system to the thermal infrared image pickup element. The temperature-controlled infrared radiation blocking body is positioned around the thermal infrared image pickup element. The thermal infrared image pickup element is mounted on a first temperature control means used to control a temperature of the thermal infrared image pickup element.

Abstract: A thermal infrared detector system includes a heat sink, a support member, a connection support member connecting the support member to the heat sink and including a heater unit. An infrared detector element is mounted on the support member and a temperature signal representative of the infrared energy contacting the support member can then be derived by comparing the temperature of the support member and the heat sink. The temperature signal from a support member and a temperature signal from the connection support member can then be used to drive a heater unit mounted on the connection support member to thereby control the thermal conductance of the support member. Thus, the thermal conductance can be controlled so that it can be actively increased or decreased as desired.

Abstract: A sensor/cooling system (20) includes a cold finger (46) with an endcap (54) having an end projection (56) at a first end (44) thereof. The end projection (56) defines a recess (58) in an end of the endcap (54), preferably along a longitudinal centerline (60) of the cold finger (46). A support structure (29) has a platform (30) with a first side (40) and a second side (42) oppositely disposed from the first side (40). The second side (42) is affixed to the end projection (56) of the endcap (54) so as to overlie the recess (58). A sensor assembly (28) is affixed to the first side (40) of the platform (30), a cryogenic cooler (50) is affixed to a second end (48) of the cold finger (46), and a vacuum housing (24) encloses at least the sensor assembly (28).

Abstract: A high responsivity thermochromic infrared detector which has an operating temperature that is established on the steepest part of the phase transition curve and is maintained there while the infrared detector is operated.

Abstract: A forward looking infrared (FLIR) device implemented using complementary metal oxide semiconductor (CMOS) techniques is disclosed. The device includes optics (10) for focusing infrared energy onto a scanner (12) for scanning across a detector array 16; a signal conditioning integrated circuit 18 for producing television compatible video signals from the detector array outputs which are electrical signals representative of the infrared energy impinging thereon; and a monitor (2) for displaying the video signals. The detector array and signal conditioning IC are mounted on a metallized ceramic chip affixed within a DEWAR (19). Electronics (20) ancillary to the signal conditioning IC is located outside the DEWAR.

Abstract: A radiation detector includes a plurality of detector elements arranged on a detector substrate in an interdigitated linear array. A thermoelectric or other cooler is attached to the lower surface of the detector substrate. A pair of interconnect boards is positioned on opposite sides of the detector substrate. The detector elements, substrate, cooler and pair of boards are received in a sealed housing and a radiation transmitting window in the housing permits radiation to pass into the housing and strike the detector elements. A plurality of conductive pins extends through the housing and terminates at electrical traces on the interconnect boards. A thermistor or other temperature sensor is attached to the detector substrate and, through control of the thermoelectric cooler, maintains the detector substrate at a desired operating temperature.

Abstract: An infrared optical system incorporates a lens for imaging a remote scene onto a detector within a cold shield. Stray radiation incident on the detector is reduced by an optical stop in the form of a light emitting diode producing negative luminescence. The LED emits less radiation than background, and contributes less to the detector photon noise than an optical stop not exhibiting negative luminescence.

Abstract: Optically readable radiation-displacement conversion devices and image-rendering apparatus that incorporate same are disclosed. Also disclosed are related methods for detecting images and rendering images using such devices and apparatus. Such devices, apparatus and methods allow improved accuracy and sensitivity of radiation detection without having to use a cooler. A representative conversion device includes a substrate and a suspended portion attached to the substrate via a leg portion. The conversion device includes a radiation-absorbing film that receives and absorbs and incident invisible radiation (e.g., UV, IR, or X-rays) and generates heat from the absorbed radiation. The suspended portion includes a displaceable member that exhibits a displacement with respect to the substrate. The displacement also imparts a change to an incident readout light flux in accordance with the magnitude of the displacement. The change to the readout light is detected and used to form an image.

Abstract: A cryogenic cooler and a dewar assembly including a cooled surface; a cooling surface for removing thermal energy from said cooled surface; and an adapter disposed between said cooling surface and the cooled surface for conducting thermal energy therebetween. A first fluid is disposed between the cooled surface and the adapter for conducting thermal energy from the cooled surface to the adapter. A second fluid is disposed between the cooling surface and the adapter for conducting thermal energy from the adapter to the cooling surface whereby the cooling surface remains free to move axially relative to the adapter at a temperature of the cooling surface at which the first fluid is susceptible to freezing. This allows for movement of the cold finger relative to the dewar and adapter, due to differential thermal coefficients of expansion or support structure motion, without adversely affecting the communication of thermal energy from the load.

Abstract: An infrared radiation detector device has a cooled detector element (3) within a first optical device (internal cold shield (1.sub.i)). The first optical device includes a first diaphragm (6.sub.i) in front of said detector element. The infrared radiation detector device has a second optical device (external cold shield (1.sub.a)) which is thermally separated from the first optical device. The second optical device includes a second diaphragm (6.sub.a). The aperture (7.sub.a) of the diaphragm forms the pupil of the infrared optic which produces an infrared image on the surface of said detector element (3).

Abstract: Thermoelectric sensor (12) formed by a membrane (14) including a plurality of thermoelectric elements (20) formed of a plurality of thermoelectric couples and forming a plurality of elementary cells. Each elementary cell is thermally insulated from adjacent elementary cells by metal wires (22, 23), preferably gold wires, arranged on the front face (25) of the membrane (14), more particularly, on an upper passivation layer (30). The metal wires (22 and 23) are thermally connected to a substrate (16) supporting said membrane. The two wires separating two adjacent thermoelectric elements (20) are separated from each other by an intermediate low thermal conduction region (28).

Abstract: A multi-band pupil stop is disclosed for use in multi-band focal plane array imaging systems. The object is to provide similar point spread functions at the focal plane array. The pupil stop is comprised of one or more nested annuli. Each annulus is a pass-band filter with the outermost annulus passing the longest wavelength waveband and each successive inner annulus passing a successively shorter wavelength waveband. The pass-band of each annulus is such that the ratio of the center wavelength of each pass-band to the outer diameter of each annulus is approximately equal.

Abstract: A method of making and a bellows cold shield wherein only the focused IR energy from the optical system of an IR detector will reach the detector or focal plane array, FPA, and all other radiation will be redirected from reaching the FPA through the use of a bellows cold shield having a predetermined geometrical surface which reflects the undesired light energy away from the FPA, and a microrough interior surface of this geometrical shape which absorbs any of the undesired light energy which is not so reflected away.

Abstract: An electrically cooled detecting system comprises: two or more heat regenerative refrigerators each having a cylinder with a cooling head at its one end; a holder for supporting the two or more heat regenerative refrigerators to dispose the one ends of the cylinders along a certain plane and the other ends of the cylinders on one side of the certain plane; a connector for thermally and rigidly connecting the cooling heads; and a detector being thermally connected to the connector. This system is not necessary to use liquid nitrogen. This system is compact and has a high energy resolution.

Abstract: A universal focal plane DEWAR assembly for cryogenic cooling of an infrared detector DEWAR, which includes an infrared transmissive window attached to a hollow support cylinder under vacuum conditions, with a glass bore in the cylinder, which contains focal plane infrared structure inside of a cold shield, which is attached to a cold plate, with a cold button in contact therewith, and with a cold finger from a cryogenically cooled expander, which is spring mounted in the glass bore for removal and replacement without disturbing the focal plane structure.

Abstract: An infrared thermal sensor assembly for sensing the temperature of a target, the sensor assembly including a heat sink having a bore therethrough; a thermopile housed in the bore; and a heater operative to heat the heat sink.

Abstract: A spectroradiometer images a scene as a repeating sequence of spectral images, each of which spectral images depicts the scene at a preselected wavelength. In a preferred embodiment, the image is of size 256 by 192 pixels, and the sequence repetition rate is about 20-30 cycles per second. Full spectral analysis on the resulting sequences is performed substantially in real time. The spectroradiometer includes a collector of energy in the X-ray or infrared ranges with a lens, a circularly variable spectral filter, and a gate which gates the output of the filter to a detector array which outputs the sequence of electronic spectral images. These images are corrected for systematic errors and calibrated, and correlated with a preselected spectral response function. The image may be further post-processed and displayed in video format or used otherwise.

Abstract: A hollow thin walled shell with integral internal baffles is formed by a multilayer coating process. A series of mandrels is designed to be assembled to form the outer surface of the desired shell. The mandrel surfaces hidden during assembly include the areas intended to form the internal baffles. The mandrels are coated separately, assembled, and the assembly is given a continuous overcoating that holds the assembly together and provides the shell with mechanical integrity. The assembly is machined to remove all internal and external coated surfaces not intended to be included in the shell and the mandrel is dissolved or otherwise removed, leaving the thin coatings as the desired shell with baffles at the areas where the coated mandrel surfaces were hidden during assembly.

Abstract: An infrared transmission window 4 is placed on the front of a light reception part 2 formed on a substrate 1 with a cavity 3 between and is bonded to the substrate 1 in airtight relation on a bond face in the range surrounding the light reception part 2, whereby the transmission window 4 is fixed and the cavity 3 is evacuated of air.

Abstract: A solid object carrying a catalyzer thereon is placed in a closed reaction chamber into which test gases are supplied and is heated up to a temperature of 1000.degree. C. Adsorbates are formed on the surface of the solid object under the test gas flow in the closed reaction chamber. Infrared radiations radiated from the adsorbates are emitted through an infrared-transmissive window hermetically formed on a wall of the closed reaction chamber, and are analyzed by an infrared radiation spectrometer and observed by a microscope. The infrared-transmissive window is cooled down by a cooling device attached thereto so that the temperature of the window does not exceed a certain level, e.g., 200.degree. C. Thus, the adsorbates formed on the solid object can be detected and analyzed under conditions where the test gas is actually flowing and the temperature of the solid object is elevated up to a high level.

Abstract: An electromagnetic detection unit for detecting infrared radiation having an electronic detection circuit with a readout joined thereto by indium microspheres, and further having a thermally conducting support, affixed to a cold source, having a good thermally conducting intermediary component located thereon and fastened to a detection unit by adhesive bonding and to the support by adhesive or brazing wherein the dimensions of the elements of the intermediary component are selected to compensate for the intrinsic effects of differential expansion of each of the constituent materials.

Abstract: A spectroradiometer images a scene as a repeating sequence of spectral images, each of which spectral images depicts the scene at a preselected wavelength. In a preferred embodiment, the image is of size 256 by 192 pixels, and the sequence repetition rate is about 20-30 cycles per second. Full spectral analysis on the resulting sequences is performed substantially in real time. The spectroradiometer includes a collector of energy in the X-ray or infrared ranges with a lens, a circularly variable spectral filter, and a gate which gates the output of the filter to a detector array which outputs the sequence of electronic spectral images. These images are corrected for systematic errors and calibrated, and correlated with a preselected spectral response function. The image may be further post-processed and displayed in video format or used otherwise.

Abstract: A radiation detector having an evacuated envelope, a radiation detector on a cold finger support in the evacuated space, a closed cycle gas cooling system to cool the cold finger to provide cryogenic operation of the radiation detector, and a getter in the evacuated space to maintain an evacuated condition. The evacuated envelope includes a radiation window. The radiation detector is preferably an X-ray detector employed in an energy dispersive spectrometry system. The evacuated space is preferably held at a pressure of less than about 1 mTorr to achieve molecular flow of remaining gas molecules, minimizing parasitic heat input. The closed cycle gas cooling system employs compressed refrigerant, which is precooled in a counterflow heat exchanger and allowed to expand in proximity to the cold finger, thus absorbing heat and maintaining cryogenic temperatures. A getter material, preferably activated carbon, is provided to absorb gasses and maintain the low pressure during operation.

Abstract: In general, the spatial resolution and repeatability of results using infrared detectors for examining printed circuit cards has been so poor that the devices have failed to achieve commercial success. These problems are overcome by a system including an isothermal enclosure for receiving a card to be tested, an infrared camera in the chamber defined by the enclosure, sensors for monitoring the temperature of the card and ambient temperature conditions in the chamber to derive signals indicative of the temperatures, and a computer connected to the camera and to the sensors for examining all signals to produce a three dimensional image of the sample, variations in the image from sample to sample being indicative of an anomaly in a sample.

Abstract: A thermal shunt apparatus directs heat flux transmitted through electrical signal leads from a focal plane array (FPA) to a relatively isothermal top surface of a TE cooler. The FPA mounts with a first thermally conductive attachment to a thermal spreader plate that is highly thermally conductive. The thermal spreader plate is mounted to the top surface of the TE cooler by a second thermally conductive attachment. The combination of the relatively isothermal surfaces, the FPA thermal spreader and the TE cooler top plate, separated by the thermally conductive interface, maintains a relatively constant temperature difference between the electrical leads connected between the thermal shunt and the FPA edge. The constant temperature difference provides for constant heat flux between these points and a constant temperature gradient across the surface of the FPA.

Abstract: A dual-band optical system 10 preferably for use in the thermal infrared waveband provides initial detection of a target in a first waveband (8-12 .mu.m) having a wide field of view and discriminated target recognition in the second waveband (3-5 .mu.m) at higher magnification and narrow field of view without any field-of-view change mechanism. The system 10 comprises a detector array 11 which is responsive in both wavebands and an optical arrangement 16 with a common objective component 15 for both wavabands. One waveband is transmitted through dichroic beamsplitters 17,18 to the array 11 whereas the other waveband is reflected by the beamsplitters 17,18 and transmitted through a field lens 28 before reaching the array 11. Both wavebands are incident upon a spectrally selective aperture stop 20 providing a large aperture for the low magnification field and a small aperture for the high magnification field.

Abstract: A focal plane array (FPA) including a layered composite structure having several layers of materials with differing thermal expansion coefficients (TECs) and thicknesses to stabilize and maintain FPA performance during thermal cycling and excursions. An optical substrate is coupled to a multiplexer through a network of indium bumps. The typical TEC mismatch of the layered materials is offset by particularly selecting the types of materials used and the thicknesses of the individual layers of the FPA. Consequently, undesirable deflections and distortion of the multiplexer and the indium bumps are minimized, thereby substantially improving FPA reliability.

Abstract: An infrared (IR) microlens array has a plurality of microlenses (12) aligned with respective IR detector array pixels (6) to focus incoming IR radiation onto the pixels (6) to improve the efficiency of IR detection, and a gas molecule getter grating (14) inside a vacuum-sealed Dewar assembly that houses the detector array (4) increases the surface area of the getter (15) to improve the efficiency of removing residual gas molecules from the Dewar assembly.

Abstract: An imaging system (10) contains a diffractive optic lens (14) which allows for a relatively accurate representation of objects within a field of view. These objects are associated with light rays (20, 22 and 24) which are made to impinge upon the diffractive optic lens (14) and thereafter are made to be received by an imaging surface (12) at a receiving angle which may be determined by the structure of the diffractive optic lens (14). The diffractive optic lens (14) may be placed within the typical dewar (16) of the image acquisition system (10), may be removable deployed over the imaging surface (12), or alternatively, the diffractive optic lens may be etched upon the front side of the imaging surface (12) by the use of standard etching techniques such as lithography, diamond turning and the like.

Abstract: The present invention is a directional reflectometer that measures the optical bidirectional reflectance distribution function [BRDF] of a surface in situ on a finished article, e.g. a vehicle, to provide information on its surface emissivity. The light wavelength may be IR, near-IR or visible. Light, preferably focused to a small spot on the surface, is projected onto the surface at an angle adjustable in azimuth and elevation. A wide angle mirror and/or lens system transfers light scattered from the surface onto an imaging sensor, preserving scattering angle information and thereby permitting the BRDFs for a given incidence angle and all scattering angles to be measured simultaneously. A hand held or laptop computer sets the incidence angle, reads the sensor outputs and renders judgments on the quality of the surface in a factory or field environment.

Abstract: A device is provided for the detection of infrared radiation which operates at low temperature. The device contains a detection unit and a cryostat equipped with a cold finger to exchange heat with a cold source. Included is a cold plane having at least one machined portion, each portion having a recess toward the center of the cold plane in the region of a through-slot opening outside the cold finger. A connection element is positioned by insertion into each recess, and is electrically connected to the connector of the cryostat.