Abstract:
A radiation detection apparatus, such as for the detection of infrared radiation, is formed of inner and outer cylindrical stainless steel vessels with the inner vessels supported from the top wall of the outer vessel by a thin, relatively long stainless steel tube. A heat transfer mounting member is attached to the bottom of the inner vessel and extends outwardly and then upwardly between and out of contact with the vessels to the position of a window opening within the outer vessel. A detector device is affixed in good thermal contact with the mounting member at the position of the window and thus is maintained substantially at the temperature of the bottom surface of the inner vessel. The surfaces of the inner and outer vessels may be highly polished to prevent heat transfer to the inner vessel by infrared radiation. The use of stainless steel for the outer vessel also allows utilization of a vacuum port window structure having a metal gasket to minimize potential gas infiltration.
Abstract:
A multicolor or other multilevel infrared detector comprises at least one first detector element formed in a first portion of a lower body, e.g. of cadmium mercury telluride. At least one second detector element, having different detector characteristics, is formed in an upper body, e.g. of cadmium mercury telluride. The lower body is divided, preferably by ion etching into at least two (and more usually three or more) portions separated from each other by gaps. The gaps in the lower body are bridged by the upper body. Electrical connections to the second detector elements comprises the separate portions of the lower body. The electrical connections include metallization layers extending from the top to the substrate on which the lower body is mounted. The substrate may be of insulating material, e.g. sapphire, or it may be for example a silicon CCD for processing signals from the detector elements.
Abstract:
An array of photovoltaic infrared radiation detector elements are formed in a body of infrared-sensitive material, e.g. of cadmium mercury telluride. The body is present on a circuit substrate, which may comprise a silicon CCD for processing signals from the detector elements. An array of regions of a first conductivity type, which form the p-n junctions of each detector element with an adjacent body part of opposite conductivity type, extend through the thickness of the body at side walls of an array of apertures. Each aperture is associated with a detector element and is preferably formed by ion etching. These regions of the first conductivity type are electrically connected to substrate conductors in a simple and reliable manner by a metallization layer in the apertures, without rendering a significant area of the detector insensitive to radiation imaged onto the upper surface of the body. At least the back surface of the detector body has a passivating layer over the area around and between the apertures to enhance detector element performance. This back surface is secured to the circuit substrate by a layer of electrically insulating adhesive. The main body part is connected to a substrate conductor by a metallization at a surface portion which is outside of the area of the back surface and which is between the apertures. The resulting device is a closely-packed array of high performance detector elements on a circuit substrate. The spacing between adjacent apertures is 100 microns or less.
Abstract:
In the manufacture of an infrared radiation detector device, a body of p-type cadmium mercury telluride is bombarded with ions to etch away a part of the body. From the etched-away part of the body an excess concentration of mercury is produced which acts as a dopant source converting an adjacent part of the body into n-type material. The energy of the bombarding ions is less than 30 keV. By appropriately choosing the ion dose this conversion from p-type to n-type can be effected over a depth considerably greater than the penetration depth of the ions. A p-n junction can be fabricated in this way for a photovoltaic detector. The conductivity type conversion may even be effected through the body thickness. The etching and conversion can be localized by masking part of the body surface against the ion bombardment.
Abstract:
The inventive method compensates for blinks occurring during examination of the eye by an objective refractor. An analog signal is produced as a function of the focus of a light pattern reflected from the eye, and the signal is processed and fed to an analyzer for determining the refractive error of the eye. The input to the analyzer is delayed to follow the analog signal by a predetermined delay. Meanwhile, any rate of change of the analog signal exceeding a predetermined thresh-hold is detected to represent the beginning of a blink, and a blink commencement signal is produced and used to stop the examination of the eye for a predetermined blink interval exceeding the expected duration of the blink. Also, the analyzer ignores the portion of the analyzer input devoted to the blink interval.
Abstract:
An apparatus for detecting radiation emanating from a source movable along a path has an elongated radiation-sensitive electronic semiconductor of a first crystalline phase. The semiconductor is positionable substantially parallel to the path. Inclusions of a second crystalline phase are contained in the semiconductor and have an electrical conductivity higher than the first phase. The inclusions are orientated substantially perpendicular to the current flow in the semiconductor response to the radiation. Two magnetic structures are disposed one behind the other laterally of the semiconductor along its longitudinal dimension and have respective magnetic fields which penetrate the semiconductor in mutually opposite directions.
Abstract:
THE INVENTION HERE DISCLOSED IS AN INDIUM ANTIMONIDE INFRARED DETECTOR AND A PROCESS FOR MAKING THE SAME. A DIFFUSION PROCESS YIELDS A VERY SHALLOW P-REGION ON AN N-TYPE INDIUM ANTIMONIDE SUBSTRATE. THIS LAYER HAS A THICKNESS OF 1.0 TO .5 MICRON AND HAS A HIGH CONCENTRATION OF ACCEPTORS, PROVIDING A VERY EFFICIENT COLLECTION REGION OF CARRIER CREATED BY PHOTON ABSORPTION. THE LAYER IS OF CADMIUM OR ZINC AND THE CONCENTRATION IS WITHIN A RANGE SUCH THAT WHILE LATTICE DAMAGE OCCURS DETECTOR OPERATION IS NOT IMPAIRED. THE LAYER IS SO SHALLOW THE MOST OF THE CARRIER CREATED BY PHOTON ABSORPTION ARE COLLECTED.