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 method for deflecting a fluid supply using a skirt. The skirt comprising a remote and a close portion (with respect to distance from a fluid impinged surface). The skirt is located in close proximity to a surface to be impinged by the fluid. The deflection method is especially suited for use in conjunction with a Joule-Thomson cryostat and can also be used in conjunction with more than one cryostat for cooling of electronic devices. The remote portion of the skirt is disposed around the nozzle or nozzles of the fluid supply so that each fluid supply (or nozzle) extends through a hole in the remote portion of the skirt. The interior surface of the close portion of the skirt extends closer to the fluid impinged surface than each nozzle. The method efficiently wets the impinged surface with a fluid providing a measure of control over the outward velocity of the fluid as it progresses along the fluid impinged surface.

Abstract: A focal plane array (FPA) mounted in an imbalanced configuration including several layers of materials with differing thermal expansion coefficients (TECs), moduli of elasticity, and thicknesses to maintain surface planarity and improve the reliability of the FPA during thermal cycling and excursions. An optical substrate is coupled to a multiplexer through an array of indium bumps. The typical TEC mismatch between the optical substrate and the multiplexer is eliminated by forcing the multiplexer to exhibit an effective TEC equal to that of the optical substrate by particularly selecting the types of materials used and the thicknesses of the individual layers of the composite structure. Consequently, undesirable deflections and distortion of the multiplexer and the indium bumps are minimized, thereby substantially improving FPA reliability.

Abstract: A skirt for deflecting a fluid supply comprises a remote and a close portion (with respect to distance from a fluid impinged surface). The skirt is located in close proximity to a surface to be impinged by the fluid. The skirt is especially suited for use in conjunction with a Joule-Thomson cryostat and can also be used in conjunction with more than one cryostat for cooling of electronic devices. The remote portion of the skirt is disposed around the nozzle or nozzles of the fluid supply so that each fluid supply (or nozzle) extends through a hole in the remote portion of the skirt. The interior surface of the close portion of the skirt extends closer to the fluid impinged surface than each nozzle. The skirt efficiently wets the impinged surface with a fluid providing a measure of control over the outward velocity of the fluid as it progresses along the fluid impinged surface.

Abstract: An infrared detector includes an outer cylinder having an infrared permeable window and an inner cylinder accommodated in the outer cylinder. The inner cylinder has an end surface, a cylindrical side surface, and an annular tapering surface formed between the end surface and the cylindrical side surface. The annular tapering surface has a diameter continuously decreasing toward the end surface. A multiple element type infrared sensor is mounted on the end surface of the inner cylinder, the infrared sensor having a plurality of output electrodes. A cryogenic cooling arrangement is provided for cooling the infrared sensor to low temperatures, and a signal fetching arrangement is provided for carrying a signal detected by the infrared sensor, the signal fetching arrangement including wiring patterns formed on the end surface, the tapering surface and the cylindrical side surface of the inner cylinder.

Abstract: A hand-held probe system for imaging is described which includes a hand-held probe and a detector assembly connected by a fiber optic cable. The probe includes a hand-portable housing, a detector assembly within the housing and an IR sensor placed on the cold finger of the detector assembly. The probe can include an optical system at a known distance from the sensor and a spacing tube defining the distance between the body and the optical system. The spacing tube ensures that the body whose thermal image is being read is always at, or is very close to, the object plane of the probe. The spacing tube is typically formed of a material having minimal thermal deformation which can minimize stray IR radiation.

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: A miniatured semiconductor radioactive ray detector which has an energy resolution substantially equivalent to that of a conventional semiconductor radioactive ray detector without use of liquid nitrogen and is simple as well as readily portable is disclosed. A Stirling type electric refrigerator is provided for cooling the semiconductor radioactive ray detecting element to the temperature near to a cryogenic temperature of liquid nitrogen. The first stage amplification circuit of the signal preamplifier for amplifying the detected signal relating to the radioactive ray and the signal line as well as circuit wiring are covered and molded by a fibrous material having gas permeability and electric insulation properties so as to reduce microphonics which are likely to be generated due to the electric refrigerator. The compression pump associated with the electric refrigerator is fixed to the support base by way of the vibration absorbing material which absorbs the vibration caused by the compression pump.

Abstract: A demand-flow Joule-Thomson cryostat 10' adapted for use with multiple coolants uses a replaceable coolant supply reservoir 21' to fill a coolant flow control bellows 17' within the cryostat with the same coolant used to provide refrigeration to the thermal load 15'. Upon termination of the cooling cycle, the bellows 17' is drained of coolant and thus prepared for operation from a different coolant supply 21' that may contain a different cryogen.

Abstract: An optical spectrometer system that includes an optical element having a two-dimensional, curved, reflective, low emissivity slit body, or surround, in which an imaging slit is formed. The optical spectrometer system includes a detector, such as an infrared detector, for example, disposed in a cavity at a focal plane thereof, an optical system in the cavity for focusing radiation onto the detector, and an entrance pupil disposed in the cavity. The curved slit body effectively and substantially eliminates out-of-field radiation from impinging upon the slit body, and its low emissivity greatly reduces self-emission from the slit body. The reflective slit body is a low emissivity element that images the detector back upon itself and passes background energy that falls within a cone defined by the entrance pupil. By using the two-dimensional curved slit body, a relatively small detector dewar or focal plane cooler may be employed in the optical spectrometer system to cool the detector.

Abstract: A detecting device having: a compressor driven by an electric signal for supplying and recovering He gas at an operation cycle of 10 Hz to 400 Hz; a He gas refrigerator for transferring the He gas to and from the compressor and expanding the tie gas to generate cold; driving power supply means for intermittently supplying a driving power to the compressor at a certain interval; and a detector to be cooled by the He gas refrigerator.

Abstract: An infrared line-scanning detector includes a scanner having an optical system, infrared linear photo-conductive detector providing an analog image signal, cooler, and conversion electronics for converting the image signal from the detector to digital electrical and digitally-encoded optical formats, all on a moving scanning platform of the scanner. The digitally-encoded optical format of the image signal takes the form of an encoded light beam which is beamed off of the moving scanning platform to a receiver on the stationary portion of the scanner. From the scanner, the image signal is transmitted in the optical format over a fiber optic cable to a reformatting, processing, analysis, and display portion of the imager. This latter portion of the imager allows the image signal to be converted once again to digital electronic format for processing, pattern recognition, image enhancement, storage, delayed display and comparison, and display in near-real time if desired.

Abstract: A preferred temperature control strategy was devised to remove heat from the analyzer and control the optical bench temperature continuously at aim. A foil-type RTD temperature detector is fastened to the optical bench to serve as a measurement input device for a PID control strategy, which is truly aim-seeking. The control strategy employs a heat pipe technology to remove heat from the analyzer enclosure. A heat pipe utilizes a fluid (such as an alcohol) to remove heat by evaporation of the fluid at an internal air circulation heat exchanger and then recondensing the fluid at an external air circulation heat exchanger. The PID temperature controller achieves the desired temperature setpoint by manipulation of heat exchanger fan speeds. The heat removal rate can be very precisely controlled.

Abstract: A staring sensor apparatus which includes an optics assembly for providing a panoramic field of view in which the field of view in one direction is considerably larger than the field of view in the direction perpendicular thereto. A two-dimensional focal plane assembly (FPA) collects and converts an incoming optical signal from the optics assembly to an electrical wave form which depicts the energy falling on each pixel of the FPA in a discrete unit of time. The resulting pixel outputs thus represent the energy emitted from specific calibratable around the optics assembly.

Abstract: A detector interface system communicates signals between an infrared detector element maintained in a cryogenic environment and associated signal processing circuitry maintained in a non-cryogenic environment. An optical modulator disposed within the cryogenic environment in electrical communication with the infrared detector element converts the electrical output of the infrared detector element into an optical output signal representative thereof. An optical demodulator disposed in the non-cryogenic environment converts the optical output signal of the optical modulator into an electrical signal. The optical demodulator is an electrical communication with the signal processing circuitry. An optical path from the optical modulator to the optical demodulator provides thermal isolation between the infrared detector element and its associated signal processing circuitry and minimizes detector bias so as to mitigate 1/f noise.

Abstract: A matched thermal expansion support system for cryogenically cooled x-ray spectrometers is described for the purpose of holding x-ray detecting crystals precisely in position throughout large temperature changes. This thermal matching is achieved by a detector holder, having an axial thermal movement characteristic, mounted on a support having an equal, but opposite, thermal movement characteristic.

Abstract: An infrared line-scanning imager includes a scanner having an optical system, infrared linear photoconductive detector providing an analog image signal, cooler, and conversion electronics for converting the image signal from the detector to digital electrical and digitally-encoded optical formats, all on a moving scanning platform of the scanner. The digitally-encoded optical format of the image signal takes the form of an encoded light beam which is beamed off of the moving scanning platform to a receiver on the stationary portion of the scanner. From the scanner, the image signal is transmitted in the optical format over a fiber optic cable to a reformatting, processing, analysis, and display portion of the imager. This latter portion of the imager allows the image signal to be converted once again to digital electronic format for processing, pattern recognition, image enhancement, storage, delayed display and comparison, and display in near-real time if desired.

Abstract: A programmable on-focal plane signal processor having analog to digital conversion, nonuniformity correction, gamma spike compensation all digitally performed on a single silicon substrate inside a dewar. The architecture supports time delay integration and spatial filtering to increase the signal to noise ratio of the focal plane array data. The processor has programmable coefficients which may be changed while the system is operating or eliminated. The architecture provides increased signal noise ratio for infrared data and decreases the output data bandwidth from the infrared focal plane array by two orders of magnitude.

Abstract: An infrared imaging system (10) has a detector assembly (12) positioned for viewing infrared radiation from a subject (20), and a housing (18) enclosing the detector assembly for maintaining the detector assembly at a temperature lower than a temperature of an environment outside the housing, the housing having a window (42) for transmission of radiation from the subject to the detector assembly. A cold stop (46) is located within the housing and a warm stop (48) is located outside the housing for transmitting radiation via their respective apertures (50, 52) from the subject to the detector assembly. The warm stop has a planar retroreflective surface (62) for reflecting rays from the detector assembly back to the detector assembly, thereby to minimize thermal noise.

Abstract: A method for communicating a signal representative of an infrared detector element's output to electrically and thermally isolated signal processing circuitry utilizes the steps of: varying the reflectivity of a photoreflective cell in response to the output of the infrared detector element such that the reflectivity of the photoreflective cell is representative thereof; resetting the photoreflective cell when the reflectivity thereof reaches a predetermined value; optically scanning the photoreflective cell with an optical scanner which is electrically and thermally isolated from the photoreflective cell; and counting the number of times the photoreflective cell is reset so as to provide a signal representative of the infrared detector element's output.

Abstract: A cold shield having an evacuated enclosure having a first aperture therein for transmission of radiations and a baffle disposed within the enclosure having a second aperture larger than the first aperture and aligned with the first aperture and having a detector disposed on a surface thereof opposite the second window. The first aperture includes a radiation transmissive member and a radiation opaque member disposed on the surface of the radiation transmissive member and external to the evacuated enclosure. A radiation band pass filter is disposed on the radiation transmissive member. The interior of the baffle is coated with an absorptive low reflecting material and the exterior surface of the baffle opposing the first aperture is coated with an absorptive low reflecting material.

Abstract: A camera system primarily for infrared radiation having a focal plane array of microbolometer elements in a vacuum package with inexpensive thermoelectric temperature stabilization is shown. The stabilization temperature may be selected by a designer or a user over a wide range of temperatures, but room temperature use is primarily expected. The microbolometers are passive elements and the readout scheme involves a sweep of the array with a short duration pulse-high level bias current.

Abstract: An apparatus for decreasing stray radiation incident upon an infrared detector includes a concavely curved lens surface adjacent the detector, the center of curvature of which concave surface is located on the surface of the detector. This arrangement limits stray radiation originating rearward of the concave lens surface to black-body radiation emitted forward from the surface on which the detector is mounted, and the detector itself. That stray radiation may be reduced to a low value by decreasing the temperature and/or increasing the emissivity of the detector mounting surface and the detector itself. Stray radiation out of a desired wavelength band and originating forward of the rear concave lens surface may be attenuated by means of a spectrally selective filter.

Abstract: An infrared dewar-detector assembly for use as a common module which is interchangeable between various military infrared detection systems. The detector is cooled to cryogenic temperature for improved sensitivity. The dewar of the common module incorporates a metal coldfinger mounted on a base plate for attachment to an associated cryo-engine. The coldfinger supports the detector on a beryllium bridge platform. The configurations of both the platform mount and the base plate are selected to minimize the vibrations transmitted to the detector.Signal paths from the detector include ribbon cables extending within the vacuum side of the dewar and having indium dot terminations making direct connections with a ceramic feedthrough header which, on the ambient pressure side of the unit, also includes indium pocket contacts for direct connection to the plug terminals of the unit.

Abstract: A dual-band infrared sensor package for use in radar system applications is provided. The package includes two detector arrays, an InSb photodiode array sensitive in the mid-wave infrared radiation range and a HgCdTe photodiode array sensitive in the long-wave infrared radiation range. The package further includes integrated circuits which provide electrical control to and data output from the detector arrays. A three dimensional arrangement of the detector arrays, integrated circuits, and ceramic interconnecting substrates is used to provide a relatively small sensor package suitable for radar system applications so that radar signals are not obscured.

Abstract: A dual Joule-Thompson cryostat assembly (10) is provided which includes first and second concentrically aligned cryostats (100) and (102), respectively, which are disposed in the coldwell of a detector assembly (12). Each of the cryostats is connected to a source of pressurized gas which is discharged into the coldwell. The pressurized gas is directed at the components to be cooled such that the relatively high discharge velocity produces a relatively high film coefficient for maximizing heat transfer. Both the inner and outer cryostats, (100) and (102), respectively, of the dual cryostat assembly (10) are designed to direct pressurized gas at an electromagnetic detector (26). In addition, the inner cryostat (100) directs pressurized gas toward the outer cryostat (102) for precooling the outer cryostat (102). Furthermore, the outer cryostat (102) is designed to direct pressurized gas for cooling a coldshield (50) surrounding the detector (26).

Abstract: An angle filter for restricting the range of light received by a detector functions as a "cold shield" in an infrared optical system. The angle filter either utilizes fiber optics or a thin film technology and reduces the size of an optical system operating in the infrared region while maintaining high system performance. The cold shield/exit pupil configuration of a traditional optical system is replaced by the angle filter.

Abstract: In a sensor assembly, a cooled sensor is arranged in the vacuum chamber of a Dewar vessel. The Dewar vessel has an inner housing element and an outer housing element. Both housing elements are made of metal and are pot-shaped. The outer housing element extends around the inner housing element. The two housing elements define the vacuum chamber of the Dewar vessel. The inner housing element carries the sensor on its end face within the vacuum chamber. A cooler is arranged in the cavity formed by the inner housing element. A tubular support body made of multi-layer glass-ceramic material is arranged in the vacuum chamber and surrounds the inner housing element. The support body supports the inner housing element through radial projections and contains conductors for connecting the sensor.

Abstract: Mercuric iodide detector systems are made less power consumptive and smaller by employing a single Peltier cooler rather than the two required by prior art systems. The optimal temperature requirements (and thus leakage current conditions) for the two critical temperature sensitive components for such a system are met by cooling the components to a reference temperature using a single cooler and by illuminating the detector to achieve the required operating performance. The elimination of the extra cooler not only conserves power and reduces maintenance requirements, but also reduces size. The use of light to achieve the required detector and FET leakage current relation for optimum operation is permitted by the implementation of a feedback loop for automatic control of the operation.

Abstract: A cooled stray light baffle for use in an imaging system such as an infrared camera is disclosed. The baffle includes a tapered shroud portion which is shaped to just enclose the envelope of light rays which pass through the baffle. That is, space between the envelope of light rays and the inner surface of the baffle is minimized. This results in minimization of the overall surface area and mass of the baffle, which in turn results in a minimization of the refrigeration load of the system. The lower refrigeration load requires a smaller refrigerator which results in reduced system size, power consumption, vibration, cool-down time and cost of operation. The outer surface of the baffle is covered with a reflective material to reflect light photons. The inner surface is roughened and blackened to absorb stray light photons which enter the baffle.

Abstract: A photolithography test structure is provided for measuring the amount of notching associated with photolithography processing. The test structure includes a curved insulating structure placed in close spaced proximity with a conductive, interconnect structure. A pair of conductive pads are deposited at opposite ends of the interconnect structure for measuring the resistance through the interconnect. Depending upon the amount of notching associated with the interconnect, resistance readings will vary. Test areas containing notched interconnect can be compared with controlled areas specifically designed not to have notching in order to determine relative changes in resistance, and to correlate that resistance with notching magnitude. The insulating structure, interconnect structure and conductive pads are processed upon the same substrate material containing the resulting product requiring testing.

Abstract: A focal plane array uses non-contact electrical interconnects instead of indium bumps. The interconnect bump comprises one or more vacuum microelectronics devices. The non-contact interconnect provides no themally conductive path between the detector and readout. For thermal detectors, the detector is not thermally connected to the readout and thus undergoes larger temperature changes in response to infrared radiation. For cryogenically cooled detectors, the detector and readout each have separate heat sinks with separate temperature controls. The readout may thus be operated at a higher temperature than the detector. The non-contact interconnect eliminates heat leakage from the readout to the detector enabling a thermal gradient to be maintained simultaneously with a net savings in refrigerator power. The non-contact interconnect also allows for differences in thermal expansion between the detector and the readout and thus increases the reliability of the focal plane array.

Abstract: An infrared ray detecting sensor having an infrared ray detecting element located in the cool chamber of a Dewar structure comprising inner and outer cylindrical members. The chamber is evacuated to vacuum level and a getter is arranged in the chamber for ensuring the vacuum level in the chamber. A partition is arranged in the chamber between the inner end of the inner cylindrical member and the getter for forming a restricted passage and allowing communication of a gas between the getter and the infrared ray detecting element and obstructing a stray ray generated upon a radiation of the getter toward the infrared ray detecting element. The restricted passage is formed such that a ray generated upon radiation of the getter is reflected many times at the restricted passage and is dampened. The partition is roughened and colored in black.

Abstract: An infrared cold shield comprises a side wall, a top wall and at least one baffle extending across the interior of the cold shield. The top wall and baffles comprise aligned apertures. The cold shield is preferably made by securing one or more metal foil disks and aluminum mandrel segments in an alternating stacked arrangement wherein the outer edges of the metal foil disks are exposed. The assembly is then electroplated to deposit a layer of metal over the side surfaces of the mandrel segments and to capture and bond with the exposed edges of the metal foil sections. The mandrel segments are then dissolved.

Abstract: A thermal or infrared imaging system having an optical barrel, an external stop formed by a mirror, a dewar, a cold shield, a focal plane array, and multiple retroreflectors. The cold shield and focal plane array are located inside the dewar. The mirror directs desired light bundles at the focal plane array. The retroreflectors are attached to the inside of the optical barrel. The retroreflectors are arranged such that the retroreflectors exist in all lines of sight of the focal plane array, except those lines of sight associated with the external stop. Consequently, the retroreflectors do not interfere with the desired light bundles which are focused onto the focal plane array. However, all light outside of that which is focused is prevented from reaching the focal plane array by the retroreflectors. The retroreflectors are infrared retroreflectors arranged in a matrix. Each of the retroreflectors is a "concave" corner cube having low emissivity reflecting facets.

Abstract: An infrared radiation detector so adapted as to prevent the image signals from deteriorating due to the short length of leads extending within the cryogenic container with the infrared radiation sensing element accommodated within and to correspond to the increasing number of the leads and terminals, associated with a high density of elements. The infrared radiation detector is composed of an inner cylinder and an outer cylinder. The outer cylinder is disposed so as to lie in the same plane as the sub-package on which the multi-layered ceramic lead plate composed of a plurality of bonding pads for wire bonding, internally embedded lead layers, and plug-in terminals for fetching signals is mounted. The bonding pad of the sub-package is bonded to the bonding pad of the ceramic lead plate through a wire bonding.

Abstract: In a multi-stage cold accumulation type refrigerator including a compressor disposed at an ordinary temperature, a helium gas as a common operating fluid to be compressed by the compressor, and one or more expansion chambers and cold accumulators of different temperature levels; a cold accumulating member of the cold accumulators is formed of an alloy or compound containing a rare earth metal, so that the efficiency of the refrigerator can be improved. Further, a heat generation quantity due to sliding resistance of a seal is set to be smaller than a theoretical generated refrigeration quantity to be obtained on the assumption of isothermal expansion in the expansion chambers, so that the refrigerating capacity can be improved. The refrigerator is applied to a cooling device for cooling a superconducting magnet, SQUID, superconducting computer, infrared telescope, etc.

Abstract: A sample cell for infrared spectrophotometry comprises a sample holder for holding a sample to be analyzed by infrared spectrophotometry, a cool air passageway and a vortex tube. The sample holder includes a primary optical surface through which infrared radiation is directed to a sample contained in the holder, and the cool air passageway is adjacent the primary optical surface of the sample holder for directing a cool air stream across the primary optical surface. The vortex tube has a cool air outlet connected to the cool air passageway for supplying cool air to the passageway.

Abstract: An infrared detector wherein an infrared detecting device can be cooled efficiently without increasing thermal stresses generated in the device body owing to cooling during the operation of the detector, and intrusion of ambient light can be prevented. A container for the infrared detecting device, which includes a bottom plate having a projection formed in the center thereof, is provided on an inner end portion of an inner cylinder constituting a dewar, and the infrared detecting device is placed on and secured to the projection of the bottom plate. The container bottom plate is made of an Invar, while the end portion of the inner cylinder is made of a Kovar or an Invar.

Abstract: An improved cold shielding arrangement for a scanned linear IR detector array normally having the pixels arranged in plural columns, is disclosed. The arrangement consists of a first slotted cold shield plate spaced from the array and designed to reduce the angular field of view for all pixels of the array in the scanning direction, and a composite cold shield in proximity to the individual pixels. The first part of the composite cold shield is a thicker plate, typically several mils thick having slots oriented to reduce the angular field of view in the resolution direction for the pixels in a common row.

Abstract: A heat machine comprising a displacer reciprocating within a housing. The displacer incorporates first and second independent, co-axial, overlapping regenerators. A first working volume is formed between the displacer and the housing at a hot end of the heat machine. Second and third working volumes are formed between the displacer and the housing at a cold end of the heat machine. A partition separates the second and third working volumes. A gas flow path exists from the first working volume to the third working volume via the first regenerator, the second working volume, a gas path within the partition, and the second regenerator.

Abstract: Parallel heat paths are provided by three nested tubes, the outer tube being of stainless steel and connected cantilevered to a housing at ambient temperature. The innermost tube forms a cold finger having a negligible temperature gradient and secured in thermal conductive isolation concentrically within an intermediate cold sleeve tube which is also concentric within the outer tube, the cold finger and cold sleeve tubes being made of copper. The tubes have a minimum diameter and specular facing surfaces to minimize radiation coupling which is the major source of heat transfer between the tubes. The two inner tubes have minimum thermal conductive coupling via thermal insulating tapered rings at one end and a thermal insulating support at the other end. A radiation detector is secured to the inner cold finger tube for receiving X-ray radiation from a specimen in an electron microscope. The other ends of the two inner tubes ar thermally conductively connected to a heat sink Dewar via braided copper straps.

Abstract: A thermal photodetector includes a thermal photodetector element and a support stand for supporting the thermal photodetector element. The support stand is made of a material of which heat conduction is relatively small, and is thermally connected to and mounted on a mount of which temperature is controlled to a predetermined temperature. The sizes of the support stand are determined such that the quantity of heat conduction in a heat conduction passage from the thermal photodetector element to the mount is equal to a predetermined quantity. The method of manufacturing this thermal detector includes the steps of exposing, to light, a photosensitive glass plate having a thickness corresponding to the height of a support stand of a thermal photodetector to be manufactured. The light exposure is made with the use of a mask having a shape which corresponds to the shape in transverse section of the support stand.

Abstract: An extremely thin, conically shaped sealing member is interposed between the cooling element of a cryocooler and a dewar to permit the flow of cryogenic gases in one direction toward the cold end of the cooling element where the gas liquifies and is precluded from passing past the sealing member in an opposite direction so as to maintain the cryogenic liquid at such cooling element cold end when subjected to extreme acceleration forces. The sealing member can be formed in place directly onto the cooling element or separately fabricated from flat stock and subsequently fixedly secured to the cooling element.

Abstract: An infrared detector assembly for infrared spectrometers includes a circuit board on which electronic components and an infrared detector and cooler unit are mounted. The detector unit includes a thermal electric cooler which cools the detector and transfers heat to a flange of the detector unit. A front side heat sink is mounted to the flange to dissipate heat to the air on the front side of the circuit board. Heat is also transferred from the flange of the heat detector unit by a heat conductive post or posts through openings in the circuit board to a heat sink mounted to the back side of the circuit board. The back side heat sink can include an adjustment plate to which the circuit board is detachably mounted and which is itself mounted on an assembly which allows lateral adjustment of the position of the circuit board and the detector thereon.

Abstract: An x-ray detector assembly is improved by covering the detector holder with a dielectric film to prevent contamination of the sides of the detector without covering the front of the detector. The film does not hermetically seal the detector holder.

Abstract: An optical system with a tube having an open front end and a back end, imaging optics mounted in the tube and a plurality of light reflective baffle portions rotationally symmetric with respect to the optical axis, and wherein first baffle portions are configured as ellipsoids of revolution, all with foci lying adjacent edge portions of the open front end of the tube and facing the the open front end, and wherein the second baffle portions are configured as hyperboloids of revolution facing away from the open end and inwardly of the tube.

Abstract: A control system for regulating the temperature of a heat detector disposed on a heat exchanger. The control system includes a temperature detector (42) for determining the temperature of the hot spot sensor (32), non-liquid cooling means (50,52) for cooling the detector when its temperature is above the desired temperature range, and non-liquid heating means (48,53) for heating the detector when its temperature is below the temperatures range. The control system includes control means (82) coupling the temperature sensing means to the non-liquid heating and cooling means. By keeping the heat detector at a generally constant temperature, the accuracy of the hot spot sensor on the heat exchanger is improved.

Abstract: An optical data transducer system is described which comprises a cryogenic dewar for containing an infrared focal plane array at low temperature and an optical spatial light modulator, collimated laser beam and associated optical train and detector for efficient extraction of information from the array.

Abstract: An infrared detector wherein an infrared detecting device can be cooled efficiently without increasing thermal stresses generated in the device body owing to cooling during the operation of the detector, and intrusion of ambient light can be prevented. A container for the infrared detecting device, which includes a bottom plate having a projection formed in the center thereof, is provided on an inner end portion of an inner cylinder constituting a dewar, and the infrared detecting device is placed on and secured to the projection of the bottom plate. The container bottom plate is made of an Invar, while the end portion of the inner cylinder is made of a Kovar or an Invar.