Abstract:
A detecting or monitoring device for laser radiation is able to oeprate at room temperature and employs a thin film of semi-conductor material of non-centrosymmetric lattice structure having a substantial crystallographic texture; thin film may suitably be tellurium in a film thickness of 1 to 100 .mu.m, supported on a substrate of single crystal silicon.
Abstract:
A multi-element infrared detector for thermal imaging, wherein the detector includes a main substrate, an aperture plate and a plurality of detector elements formed on the main substrate and arranged thereon in an array. Each detector element having a photosensitive zone and output and common terminal electrodes formed at opposite ends thereof. The aperture plate having at least one aperture for restricting the field of view of the photosensitive zone. The detector includes an auxiliary electrode formed on the rear surface of the aperture plate in a position to contact the common terminal electrodes when the device is assembled. The infrared detector also includes a common metal line formed on the substrate in a position to interconnect a plurality of common terminal electrodes and the auxiliary electrode contacts the common metal line.
Abstract:
A tunable infrared detector employing a vanishing band gap semimetal material which is provided with an induced band gap by a magnetic field to allow intrinsic semiconductor type infrared detection capabilities. The semimetal material may thus operate as a semiconductor type detector with a wavelength sensitivity corresponding to the induced band gap in a preferred embodiment of a diode structure. Preferred semimetal materials include Hg.sub.1-x Cd.sub.x Te, x
Abstract:
Consolidation of active and passive detectors (26, 28, 34) on a single coldfinger (20) in a dewar (10) is made possible by interposing between the detectors (26, 28, 34) an electromagnetic interference shield (64, 68) which acts as a waveguide filter blocking any interfering frequencies. The waveguide is formed by a pair of spaced interleaved shields (64, 68), one of which (64) is associated with the dewar envelope and is externally grounded, and the other of which is associated with the coldfinger (20). Photons which penetrate through the waveguide (64, 68) are deflected to the outside of the dewar (10) by a flanged narcissus shield (40) surrounding the passive detector (34). Alignment of the detectors (26, 28, 34) and assembly of the dewar (10) is greatly facilitated by constructing the envelope in several generally cylindrical sections (14, 16, 18), the lowermost one of which (14) is shorter than the coldfinger (20); and by fusing the coldfinger (20) and lowermost envelope section (14) to a metal mounting base (12) prior to the final assembly of the dewar (10).
Abstract:
A shield for limiting the radiation received by an array of detectors along the length of the detector array of an electromagnetic radiation detection system to radiation provided to the detectors by the optics of the system. The shield comprises a pair of glass rods mounted in a parallel relationship to each other and to the linear direction of the array and forming an aperture along the length of the array so as to shield the elements of the array from electromagnetic radiation generated outside the field-of-view of the detectors.
Abstract:
A radiation sensor comprises a housing, a radiation filter, and a photocell positioned to sense radiation passing through the filter. Means are provided for receiving signals from the photocell indicative of radiation sensed by the photocell. In accordance with this invention, means are provided for hermetically sealing the filter and photocell from the exterior, and also for providing cooling (and optionally heating) of the filter and photocell to hold their respective temperatures below predetermined maximum levels, for improvement of sensing accuracy and operating life.
Abstract:
An apparatus for measuring the temperature in a heating system comprising a cooking pot with cooking material positioned on a hot plate where a radiation receiver is arranged at a distance from the wall of the cooking pot and aligned with it, which receiver produces a temperature measurement signal corresponding to the temperature of the cooking material in the cooking pot. The temperature measurement signal is derived from a detected radiation area on the wall of the cooking pot which corresponds to the radiation measuring field of the radiation receiver. The effect of different distances of the cooking pot from the radiation receiver is automatically compensated for by aligning the center axis of the radiation measurement field at an acute angle to the support surface of the hot plate, so that the distance of the center of the detected radiation area from the bottom of the cooking pot increases with an increasing distance of the wall of the cooking pot from the radiation receiver.
Abstract:
A photodetector which uses a photoconductive layer for detection is provided with a load resistor which is a layer of the same material and shares the same substrate as the photoconducting layer for temperature compensation. The resistor layer is shielded from the radiation being detected while the photoconductive layer is exposed to the radiation. Advantageously, each layer has the same intrinsic resistance but the resistance layer is a scaled up transformation of the photoconducting layer.
Abstract:
An image sensing device is improved by an optical shield having a multi-aperture to provide high signal to noise ratio. The improved optical shield is provided with a plurality of shield elements forming a grid-like or cellular structure. With such a structure, the solid angle of the field of view for each sensing element becomes almost the same, resulting in the reduction of "shading". The distance between the heat shield and the array can be reduced, resulting in miniaturization of the device. Each sensing element is not shielded individually, so the pitch of the shield elements can be larger than that of the sensing elements, which allows easier and less costly fabrication of the shield.
Abstract:
In electro-optical detectors which include as elements a photoemitting photocathode and anode, a photoemitting diode is fabricated which lowers the diode's work function, thus reducing the cooling requirement typically needed for this type of device. The work function is reduced by sandwiching between the photocathode and anode a liquid medium of the formula NR.sub.3 and having an electron affinity for the electrons of the photocathode, which liquid medium permits free electrons leaving the photocathode to remain as stable solvated species in the liquid medium. Thus, highly light-absorbent, and therefore thin, metallic layers can be used for detection, thereby reducing dark current at a given temperature, with a consequent reduction in cooling requirements at constant detector performance.