Abstract: A method for bonding the ends of the conductors 52 to circuit pads 54 is disclosed whereby the cable 20 is placed over the circuit pads 54; a bonding tool 44 is pressed against an upper surface 58 of the cable 20; the substrate 46 of the cable 20 is compressed beyond its elastic limit; and ultrasonic energy is applied to the bonding tool 44 and transmitted through the substrate 46 to effect a metallic bond between the conductors 52 and circuit pads 54.

Abstract: Disclosed is a method of fabricating a two-color radiation detector, and two-color photodetectors fabricated by the method. A structure is grown upon a substrate (10) to provide, in sequence, a LPE grown LWIR n-type layer (12), a MWIR p+ type common contact layer (14), and a MWIR n-type layer (16). Following growth of the MWIR n-type layer, a layer of passivation (18) is applied, and the substrate is removed to so as to enable further processing of the structure into an array (1) of two-color photodetectors. The three layer structure is bonded, prior to further processing, to a supporting substrate (22) with an adhesive bond made to the passivation layer. The supporting substrate is comprised of IR transparent material such as Group IIB-VIA semiconductor material, Group IIIA-VA semiconductor material, Group IVA semiconductor material, sapphire, and combinations thereof.

Abstract: A radiation detector (1) includes a multi-layered substrate (2,10) having a first major surface, which is a radiation receiving surface, and a second major surface disposed opposite to the first major surface. A first detector is formed adjacent to the first major surface, the first detector being responsive to a wavelength or wavelengths of electromagnetic radiation in the range of approximately 0.3 micrometers (near-UV) to approximately 1.2 micrometers (near-IR). A second detector is formed adjacent to the second major surface of the multi-layered substrate, the second detector being responsive to a wavelength or wavelengths of electromagnetic radiation in the range of approximately one micrometer to approximately twenty micrometers (SWIR to VLWIR). In a presently preferred embodiment the second detector is simultaneously responsive to IR radiation within two distinct spectral bands.

Abstract: A Group II-VI photodetector array 12 is coupled to a silicon readout circuit 14 by means of a thermal/mechanical buffer 16 comprised of a body of material which has a characteristic thermal expansivity which is more similar to that of the thermal expansivity of the Group II-VI material than that of silicon. One suitable material is Al.sub.2 O.sub.3. The buffer has a plurality of conductive vias 18 formed therethrough, each of the conductive vias being "bumped" at opposite ends thereof. The buffer accommodates the differing expansivities of, for example, HgCdTe and silicon, thereby relieving thermally generated stresses with a consequent improvement in the reliability of the resulting hybrid structure.

Abstract: Infrared transmitting windows having a diamond support are formed by first depositing diamond (14) on a mold (10) comprising a material which can withstand the optimum diamond growth temperatures. A germanium carbide adhesive layer (18) is deposited on the diamond layer Next, ZnSe, ZnS, or other index-matching material (16) is deposited on top of the diamond coating. Finally, the mold is removed. The end product is a diamond/ZnS(e) IR window requiring little or no polishing of diamond surfaces.

Abstract: An article (30) is controllably and precisely positioned at one of three discrete locations defined by a linkage. The positioning apparatus includes two independently driven cranks (34, 42), with a link (50) pivotably connected between the two cranks (34, 42). Another connector (44) is pivotably connected between one of the cranks (34 or 42) and the article (30) to be positioned. The cranks (34, 42) are rotationally adjusted so that the pivot points (52, 54) of the link (50) are collinear with the axes of rotation of the cranks (40, 48), thereby defining one of the three discrete locations. Additional cranks and links can be provided to define additional discrete locations.

Abstract: An IR detector array (10) wherein a metal contact pad (20) makes contact to an underlying radiation detector through one or more thin, electrically conductive stripes (20a). The striped pad contact shape is used in conjunction with a highly absorptive and opaque coating (18) that is interposed between a bottom surface of the contact pad and a top surface of the radiation detector. The highly absorptive coating serves to mask the bottom surface of the metal contact pad from any radiation that would impinge thereon and be reflected. As a result, stray or unabsorbed radiation reaching to a region of the contact pad encounters only the relatively small target presented by the edge of the one or more thin electrically conductive stripes.

Abstract: A supply valve includes a first valve member formed with a plurality of ports which communicate with containers of different fluids, and a second valve member having a single port which communicates with an inlet of a chamber into which the fluids are selectively supplied. The second valve member sealingly and slidingly engages with the first valve member, and is movable by a computer-controlled motor drive relative thereto in two directions to positions in which the port of the second valve member communicates with the ports of the first valve member respectively. Each position has unique coordinates in the two directions such that the fluids can be selected in any sequence. In one embodiment, the first valve member is a cylinder having a bore with an axis and the second valve member is a piston which is coaxially received in the bore, and the two directions are rotation above the axis and translation along the axis respectively.

Abstract: A photoresponsive device and a method of fabricating same, wherein the device includes semiconductor material, such as a cap region (14a), comprised of elements selected from Group IIB-VIA. A molybdenum contact pad (16) is formed upon a surface of the cap region, and a molybdenum ground contact pad is formed on a surface of a base region (12). A wide bandgap semiconductor passivation layer (20) overlies the surface of cap region and also partially overlies the molybdenum contact pad. A dielectric layer (22) overlies the passivation layer, and an indium bump (24) is formed upon the molybdenum contact pad. The indium bump extends upwardly from the molybdenum contact pad and through the dielectric layer. The dielectric layer is in intimate contact with side surfaces of the indium bump such that no portion of the molybdenum contact pad can be physically contacted from a top surface of the dielectric layer.

Abstract: A backside illuminated array (10) of radiation detectors (12) each of which has an output terminal for expressing a center-surround output signal. The array includes a plurality of the radiation detectors (12) disposed substantially adjacent to a first surface of the array, each of the radiation detectors comprising a central radiation detector (20) having a radiation absorbing area that is substantially surrounded by a radiation absorbing area of an associated peripheral radiation detector (22). The array further includes a transmission grating structure (16) disposed over a second surface (14a) of the array opposite the first surface for diffracting incident radiation for uniformly illuminating associated central and peripheral radiation detectors. The array further includes a plurality of flux concentrating structures (18) interposed between the transmission grating structure and the plurality of radiation detectors.

Abstract: A photodiode (10) fabricated in accordance with the method of the invention includes a substrate (11) and a semiconductor base region (12) overlying the substrate. The base region is comprised of Group IIB-VIA material and has a first type of electrical conductivity. A passivation layer (16) overlies the base region and is also comprised of Group IIB-VIA material. A dielectric layer (18) at least partially overlies the passivation layer. During fabrication the dielectric layer functions as an etch stop during a removal of excess cap material, the remaining cap material forming a cap region (14) within an opening that is etched through the dielectric layer and the passivation layer. The cap region is also comprised of Group IIB-VIA material, has a second type of electrical conductivity, and forms a heterojunction (14a) with the base region. An electrically conductive contact pad (20) and an electrically conductive interconnect, preferably an indium bump (22), are formed upon the cap region.

Abstract: A semiconductor wafer (52) or other object is retained in a cell (50) such that a thin space (60) having a laterally spaced inlet (62) and outlet (64) is provided above the wafer surface (52a). A plurality of chemicals including solvents, etchants, etc. are provided in individual pressurized containers (18,20,22,24,28,44). A valve (42) connects a selected container (18,20,22,24,28,44) to the inlet (62) for a length of time sufficient for the respective chemical to fill the space (60), and also connects the outlet (64) to an individual receptacle (26,30) for the chemical. The valve (42) then disconnects the container (18,20,22,24,28,44) and receptacle (26,30) from the inlet (62) and outlet (64) and traps the chemical in the space (60) for a length of time sufficient for the chemical to react with the wafer surface (52a).

Abstract: An apparatus is disclosed for testing the integrity of an optical fiber (23) from a single end of the fiber. A test light source (34) with a wavelength that is different from the primary light source (14) is directed into one end of the optical fiber (23). A spectrally selective dichroic material (32) is attached to the other end of the optical fiber (23). This material (32) transmits light of the wavelength of the primary light source (14) and reflects light of the wavelength of the test light source (34). A break or discontinuity in the optical fiber (23) can be detected by an attenuation in a pulse of light from the test light source (34) after it is transmitted though the optical fiber (23) and reflected back out of the optical fiber (23) by the dichroic material (32). This system can detect breaks or discontinuities in the optical fiber (23) with a high degree of resolution.

Abstract: A four-layer, wideband anti-reflection coating (30) is formed on a light-receiving surface (22) of an indium antimonide (InSb) photodetector (10) to enable detection of light at visible as well as infrared wavelengths. The layers (30a,30b,30c,30d) each have an optical thickness of approximately one-quarter wavelength at a reference wavelength of 1.6 microns. The refractive indices of the layers (30a,30b,30c,30d) are stepped down from the surface (22), having values of approximately 3.2/2.6/1.9/1.45 respectively. The second layer (30b) is preferably formed of silicon suboxide (SiO.sub.0<X<1) by electron-beam deposition of silicon in an oxygen backfill to obtain a refractive index between the indices of silicon and silicon monoxide. A thin passivation layer (26) of germanium or silicon nitride is formed on the surface (22) under the anti-reflection coating (30) to inhibit a flashing effect at infrared wavelengths after exposing to the ultraviolet (UV) and/or visible light.

Abstract: An apparatus (10) and method for testing the continuity of two optical fibers (12, 14) nonsimultaneously utilizing a single optical path. Two test light beams from a dual hybrid laser (30) are collimated and directed down a single optical path time-sequentially. The two light beams are linearly polarized in orthogonal planes. A quarter wave plate (42) converts the linearly polarized light into circularly polarized light, and an optical sequencer (22) directs the circularly polarized beams to a plurality of desired optical paths, each path comprising one or two optical fibers (12, 14). A second quarter wave plate (50) converts the circularly polarized light back into linearly polarized light, and a polarizing beamsplitter (24) reflects one of the beams and transmits the other. The two beams then enter the optical fibers (12, 14), where they are reflected by dichroic mirrors (26, 28) at the opposite end of the fibers (12, 14).

Abstract: A satellite orientation detection system disposed to detect the pointing orientation of a geosynchronous satellite (10) relative to a reference location on the earth. The present invention is also capable of ascertaining the angular orientation of a longitudinal axis of the satellite (10) relative to a defined axis on the surface of the earth. A ground station (20) is included for transmitting a first linearly polarized and a second circularly polarized electromagnetic reference beam. The present system also includes a receive antenna (28) coupled to the satellite (10) for receiving the first and second reference beams and for generating an antenna-beam pattern P1 and P2 disposed to rotate about a reference axis A. A rotating polarizer arrangement (44), aligned with the receive antenna (28), periodically varies the portion of the linearly polarized energy within the first reference beam transmitted thereby.

Abstract: A wide field-of-view optical element 12 suitable for use in a laser warning system including a frusto-conical block of optically transparent material having a first surface 14 and a second surface 16. The first surface 14 is parallel with the second surface 16 and coaxial therewith. The radius R.sub.1 of the first surface 14 is less than the radius R.sub.2 of the second surface such that the sides of the element 12 are slanted. Reflective material is coated on the interior 17 of the first surface 14 for directing incident optical energy toward a detector 20 mounted at the second surface 16. Similarly, a reflective material is coated on the interior 18 of the second surface 16 for directing incident optical energy to the detector 20 via the first surface 14. The second reflective coating on the second surface is disposed between the outer periphery thereof and a nonzero distance R.sub.3 from the center thereof to provide an aperture at which the detector 20 may be mounted.

Abstract: A mercury-cadmium-telluride (HgCdTe) photoresponsive layer (14) having the composition Hg.sub.1-x Cd.sub.x Te is formed on a substrate (12) such that x increases from the surface (14a) of the photoresponsive layer (14) toward the substrate (12). This causes the bandgap in the photoresponsive layer (14) to increase from the surface (14a) toward the substrate (12), thereby urging minority carriers which are photogenerated in the photoresponsive layer (14) to move toward and be trapped at the surface (14a). Laterally spaced first and second ohmic contacts (16,18) are electrically connected to the photoresponsive layer (14) at a predetermined distance (z.sub.c) below the surface (14a) such that the photogenerated minority carriers trapped at the surface (14a) are urged away from the contacts (16,18) by the increasing bandgap.

Abstract: An alcohol sensing device is provided for determination of the alcohol content within an alcohol/gasoline fuel mixture which is being provided for the operation of an internal combustion engine. The sensing device uses infrared spectrometry measuring techniques. The infrared sensing device determines the ratio of light absorption by the alcohol/gasoline mixture at two discrete wavelengths within the near-infrared spectrum. The two particular wavelengths of interest are preferably chosen so that at one of the infrared wavelengths, alcohol is strongly absorbing while the gasoline exhibits very little absorption, and at the second wavelength both the alcohol and the gasoline exhibit are essentially non-absorbing. An alternating current is used to switch the light beam between two power settings so as to vary the intensity of transmitted light at both wavelengths. The light beam is transmitted through the alcohol/gasoline fuel mixture so that the two discrete wavelengths traverse the same optical path.

Abstract: A radiation detector capable of withstanding illumination by relatively concentrated electromagnetic energy is disclosed herein. The radiation detection system 10 of the present invention includes a sensor assembly 14 for generating radiant energy upon illumination by incident electromagnetic radiation R. The sensor assembly 14 will preferably include a sheet of metallic foil 24 for emitting the radiant energy into a sensor chamber defined by the assembly 14. The inventive radiation detection system 10 further includes an optical fiber cable 18 in communication with the sensor chamber. Radiant energy from within the sensor chamber is guided by the fiber cable 18 to a shielded detector arrangement 20 disposed to provide a detection signal indicative of the intensity of the incident electromagnetic radiation R.