Abstract:
An infrared detector has an infrared detector element (2) mounted at a first part (11) of a housing (1), a Joule-Thomson cooling element (3) accommodated in a second part (12), and an infrared transmissive window (15) at the front of the housing (1). A compact, space-saving and light weight structure with improved optical efficiency is obtained. The core of the Joule-Thomson cooling element (3) forms a third part (13) of the housing (1), and these second and third parts (12 and 13) of the housing extend towards the front of the detector. The cooler core (13) which may carry a cooled filter (25) has a hollow shape or is otherwise infrared transmissive in front of the detector element (2) and can direct incident radiation (50) towards the detector element (2). For this purpose the inner surface of the hollow core (13) may carry a reflective conductor pattern (18,19) which also provides electrical connections for the detector element (2). This core part (13) may seal a channel in a grooved intermediate member (48 in FIG. 3) between the second and third housing parts (12 and 13) so as to form the Joule-Thomson cooling element (3) without requiring conventional finned metal tubing (31 in FIG. 1).
Abstract:
A cryogenic device for radiation detectors is provided comprising an enclosure situated between a cryogenic cold finger supporting a detector and an external wall. After a brief degasification under vacuum of said enclosure, at least one gas is therein introduced, whose liquefaction or solidification temperature is higher than the temperature reached by said cold finger.
Abstract:
The present invention is directed to a method and apparatus for reducing temperature variation in an infrared detector. The apparatus comprises a coldfinger for receiving thermal energy from an infrared detector. A thermal damper is also provided for conducting thermal energy from said detector to the coldfinger by one or more thermally conductive paths. A detector mount is used for combining the thermal energy flowing through the paths, thereby reducing the temperature variation in the detector.
Abstract:
An improved detector dewar assembly in which the flange supporting the upper cap of the dewar assembly comprises a disc ceramic matrix, including buried electrical leads. This disc serves several purposes. First, it provides a vacuum tight electric feedthrough which connects a tape cable from the detector assembly to a pin assembly imbedded in the exterior portion of the disc feedthrough. Second, it includes metalizations on its top and lower surface in order to provide a surface for connecting (by brazing or soldering) the upper cap assembly and the major vessel wall. A tape cable comprising wires embedded in a flexible nonconductive matrix connects the detector element leadout wires with the electrical connectors of the feedthrough disc. The cable forms a collar which substantially surrounds the coldwell and has tabs at its basal portion which fold up to attach to pin or pad connectors on the lower surface of the disc. The use of Manganin, Constantan, or Balco wires produces a tape cable which significantly reduces the heat load on the dewar refrigerator system. Solder/bond rings and pads positioned both on the endwell and disc assembly mate to solder bond/rings and pads/dots positioned on the tape cable thereby providing stress relief.
Abstract:
The disclosure relates to an infrared detector and method of making an infrared detector having HgCdTe detectors in the same focal plane of different compositions responsive to two or more different infrared frequency windows. This is accomplished by using SiO.sub.2 and/or Si.sub.x O.sub.y N.sub.z for masking and/or isolation during liquid phase epitaxial growth of the HgCdTe. The SiO.sub.2 and/or Si.sub.x O.sub.y N.sub.z are formed by plasma deposition.
Abstract:
An infra-red detector or sensor comprises a wafer (11) of single crystal silicon in one surface of which pyramidal pits (12) forming a two-dimensional array are etched. The pits form horn aerial elements whereby radiant energy is directed to bolometers (14) one disposed at the throat of each horn.
Abstract:
A temperature responsive device, such as a fuse or a temperature measuring apparatus, is disclosed including a temperature sensor having a light reflective (or light transmissive) characteristic which varies with temperature, and a device for receiving the light reflected from (or transmitted through) the sensor and to provide an output in accordance with the state of the characteristic. As shown, the sensor (perhaps an adhesive temperature indicator) is used as a fuse and, upon its color-change, it interrupts a switch 2 connecting a power source to a load the temperature of which the sensor senses.
Abstract:
In a radiation detector including a substrate of photoconductive material having input and output contacts, the photocarrier flow-path between the two contacts includes regions of conductive material. These regions may be formed as strips overlying the substrate, or may be formed in grooves in the substrate. Alternatively, the substrate may comprise a number of separate regions of photoconductive material interconnected by regions of conductive material. The substrate is preferably of cadmium mercury telluride photoconductive material and the conductive regions of gold. Chromium may be used to provide a bond between the gold and cadmium mercury telluride. The substrate may be slotted to increase flow-path length between the two contacts.
Abstract:
A monolithic imager utilizing a plurality of detector cells for detecting the presence of radiation and producing a two dimensional mapping thereof. The detector cells are arrayed in a matrix having a square center surrounded by a number of polygonal rings so that a relatively high resolution mapping of detected radiation is achieved at the center of the imager.
Abstract:
The invention relates to a fiber optical temperature measuring device of the pyrometer type, comprising a transducer section and an electronic section, which are mutually interconnected by at least one optical fiber. The electronic section includes at least one light source and the light therefrom is arranged to be emitted via the optical fiber to the transducer, and in the transducer at least part of the light is reflected back into the fiber and is conducted through the optical fiber together with an output measuring signal from the transducer to one or more detectors included in the electronic section.