Abstract: A particular wavelength may be eliminated from the spectrum of a randomly polarized thermally radiative scene by a quarter-wave polarizer and a dielectric dispersive mirror angularly positioned at the Brewster angle for the particular wavelength. The scene radiation is linearly polarized in the plane of incidence of the mirror and the particular wavelength of the scene is transmitted. The other wavelengths of the scene whose indices of refraction are dispersive, i.e., different from the particular wavelength, are reflected and directed to a photodetector, some other radiative detecting device, or a human eye. The invention can thus provide protection from a laser or other high-power optical emitter when used as a counter-measure in a thermally radiative scene.

Abstract: Curved thermal objects emit infrared energy with different ratios of ordiy-to-extraordinary polarizations compared to flat thermal objects. The invention takes advantage of this by taking the sum or difference of or between thermal images for two different polarization images of a scene. The curved objects are enhanced with respect to the remainder of the scene on a viewer.

Abstract: The black hole which a cryogenically-cooled infrared (thermal) detector ctes in a scene being observed by another such detector is obscured by inserting a partial transmitter-reflector on the optical axis of the detector. A black-body radiator projects an ambient-temperature image the same size and shape as the black hole onto the transmitter-reflector such that the other detector sees a combined image with no apparent black hole.

Abstract: A photodiode array structure and method of fabrication is provided. The ay is fabricated on a substrate as a multilayer structure with a novel combination of different type layers and then separated into optically independent diodes by delineation of the diodes. A novel array with heterojunction diodes for far-infrared is specifically disclosed.

Abstract: A photodiode array structure and method of fabrication is provided. The ay is fabricated on a substrate as a multilayer structure with a novel combination of different type layers and then separated into optically independent diodes by delineation of the diodes. A novel array with heterojunction diodes for far-infrared is specifically disclosed.

Abstract: A series of highly-reflective contiguous conical segments about an optic s. The length of each segment side and the cone vertex angle of each cone is related to the overall desired size of the reflector, and the desired angle of radiation from the reflector.

Abstract: A method is devised for the automatic detection of a human body. The method utilizes the near-infrared reflection bands of the skin of the human body as the identifying signature. Illumination of the body is provided by a near-infrared light source and the detection of the reflection bands, three in number, is performed by three detectors, each optically tuned to one of the reflection bands. When each of the three detectors simultaneously register a signal of the proper reflection values, a coincident trigger circuit enables an indicator device which signifies a human body is detected.

Abstract: An array for light-detecting diodes is inserted into a cavity in an electally insulating substrate with trimmable resistances on the substrate. The substrate is cooled, the diodes are connected to the resistances and are energized via electrical conductors on the substrate and in the cavity, and their individual near infrared light detectivities are measured. The resistors are trimmed by a laser beam such that all diodes have the same amount of detectivity. The substrate is allowed to return to ambient temperature, is mounted on a cold finger, and electrical conductors are made between the resistance-diode combinations and connectors on the cold finger.

Abstract: A collinear aiming light image viewer device in a common housing through ch an observer may view both a target scene and a superimposed collinear aiming light beam within the viewer. The aiming light source is positioned in an offset area of the common housing to project a narrow IR beam off a partially reflective mirror along a portion of the optical axis of the image viewer onto a scene wherein the scene and IR beam images are simultaneously viewed through an image intensifier.

Abstract: A method is provided to liquify and then freeze a crystallizable stoichiometric compound so that a large well defined interface between simultaneous liquid and solid phases moves at a preprogrammed rate through the compound without moving the compound or the vessel in which it is contained.

Abstract: A modular trim resistive network providing adjustable in-circuit resistance. The network essentially consists of multiple parallel connected single or double branched series divided resistive elements of which the elements may be separate and distinct or diffused onto or into the surface of an integrated circuit. In either instance the elements are interconnected by conductive leads in such a manner that the selective severing of various leads results in the desired matching network resistance.

Abstract: A low impedance laser diode mounting structure in which the inductive reance and the capacitive reactance are balanced to leave only the pure resistance in the input to a diode. The low impedance laser diode mounting structure comprises a large diameter, conductive central electrode of one potential separated from a conductive housing of the opposite potential by a layer of insulation, such as glass frit. The width of the insulation layer is such that the capacitive reactance caused by the capacitance included between the input electrode, which is generally of positive potential, and the housing, which is usually at ground potential, is equal to the inductive reactance included in the short lead of the input electrode. The input electrode and housing may be made of copper, brass or other high conductivity metals.One side of the diode is mounted on a heat sink that is electrically connected to the housing. A short lead, made of copper or gold, connects the input electrode to the other side of the diode.