Abstract: Hermetically sealed optical fiber arrays comprising a bundle of metal-coated optical fibers which are sealed to each other and to a metal-coated supporting structure. The hermetic seals are formed by a process which uses fluxless solder and preferably a vacuum to enhance application of the solder.

Abstract: A thermal transfer adhesive composition which is applied after electronic components have been installed on a printed wiring board, comprising:(a) 30 to 70 weight percent of an aliphatic diisocyanate or triisocyanate prepolymer;(b) 5 to 15 weight percent of a polyether diol or triol;(c) 20 to 40 weight percent of castor oil;(d) 5 to 20 weight percent of an epoxy resin containing 2 or more hydroxyl group;(e) 0.006 to 0.008 weight percent of a catalyst for the reaction of isocyanate groups with hydroxyl groups. The cured product is hydrolytically stable at 185.degree. F. and 95 percent relative humidity and has a good storage life when frozen. Alternatively, the composition may also include a pigment.

Abstract: Copper-containing multilayer substrates are etched, and stringers formed in the plated through-holes in these substrates are simultaneously removed by treatment with an aqueous composition including about 37% by weight hydrofluoric acid and about 16% by weight nitric acid. The same aqueous composition can be used to remove stringers formed during treatment of such substrates with other etchants.

Abstract: A methane Raman cell is provided with a catalytic composite comprising palladium on a titania substrate, which promotes the hydrogenation of gas products formed by the decomposition of methane from arcing, and thereby inhibits the reaction of these gas products to form deposits which adhere to the windows of the Raman cell. This Raman cell has greatly increased life. In an alternative embodiment, further improvements may be obtained by adding hydrogen dopant gas to the methane.

Abstract: A Coriolis mass flow meter for measuring the volume of mass flowing through a conduit. The flow meter includes at least one flow tube through which the mass to be measured passes. The flow tube is vibrated at a selected frequency that produces a resultant oscillation which is dependent upon Coriolis forces generated by the flowing mass. The oscillations of the flow tube are measured optically utilizing an optical fiber measurement system comprising a loop of optical fiber capable of producing microbend-induced optical attenuation, which is coupled to the flow tube, an optical signal source, an optical detector means, and means for determining the modulation of the optical signal between the input end and the output end of the optical fiber. Preferably, the optical fiber is metal-coated.

Abstract: A solid lubricated resistive ink includes solid lubricants which provide self-lubrication of the resistive ink under high vacuum and low moisture conditions. The resistive inks include a polymer-based binder and an electrically conductive solid lubricant which remains electrically conductive and lubricative under low moisture and high vacuum. Effective lubricants include MoSe.sub.2, NbSe.sub.2 graphite intercalated with bromine and graphite intercalated with a metal chloride. The resistive ink may additionally include carbon.

Abstract: An improved silicon chip metallization system for use in attaching silicon chips to substrates. The improvement comprises providing a layer of titanium between the silicon chip backside and the layers of chrome and gold which are conventionally used as the backside metallization. The layer of titanium adjacent to the silicon chip backside reduces silicon dioxide formation during chip attachment procedures carried out in non-vacuum environments.

Abstract: A system and method for measuring viscosity of a layer of wet paint on a surface by deforming the layer of paint, measuring the response of the deformed layer of paint, and determining the viscosity based on the measured response.

Abstract: An integrated multi-spectral target generator for use with electro-optical systems that comprise visible and infrared sensors and a laser designator. A pinhole is illuminated with a multiband source to produce a single visible and infrared target which is detected by visible and infrared sensors. A pair of beamsplitters and an associated corner reflector precisely define the parallelism of the visible and infrared radiation transmitted from the multiband source along an optical axis. A reflective telescope is used to project the visible radiation to the visible sensor and the infrared radiation, in conjunction with a periscope, to the infrared sensor. The target generator does not require precision stabilization and uses a single inherently parallel path to generate visible and infrared boresight targets. The target generator enables a boresight procedure to be completed in about ten seconds without firing the laser designator.

Abstract: A crystal modulator (20) is on an axis (19) which is positioned in translation and pivotal rotation with respect to another axis (17) of a laser. The crystal modulator (20) is supported in an inner housing (18) on axis (19). The inner housing is supported within an outer housing (16) which is affixed to the laser. Mating surfaces (32, 38) on the inner and outer housings are spherically contoured so that the inner housing may be pivoted about the center (24) of the extended sphere of the mating surfaces and thereby pivot axis (19) into coincidence with axis (17). An end (22) of the crystal modulator is positioned at this spherical center. Of two sets of four setscrews (26, 28) threaded into the outer housing, one set is disposed to contact the inner housing directly. The other set of screws is disposed to contact a ring (36) whose inner surface comprises one of the spherical surfaces.

Abstract: A process for forming a single-notch optical filter having a continually and accurately varying periodic profile. An optical medium is coated on a uniform substrate where the homogeneous optical medium produces a rugate filter, so that the profile of the refractive index follows a sinusoidal pattern and Bragg's law. As the optical medium is coated on the substrate, the depositing film is monitored by optical techniques, and feedback information is provided to a computer driven by a pre-programmed process control algorithm so that real time control of the manufacturing process may be accomplished.

Abstract: Integrated laser head apparatus is disclosed for producing high energy pulses in pulsed gas lasers. The present invention provides high energy pulses over short time durations suitable for laser rangefinder systems due to an improvement in the arrangement of energy storage capacitors (22, 24) which keeps circuit inductance to a minimum. The pair of nested, ceramic capacitors (22, 24) are substantially cylindrical and are coupled through thin conductive layers (23). The capacitors are charged by a spark gap trigger (14), an inductor (18), and a charging resistor (52). The capacitors (22, 24) enclose a pressure vessel (28) which further encloses a laser resonator (12) including a laser output coupler mirror (42), totally reflective mirror (44), discharge electrodes (32, 34) and a central chamber (30) which contains a pressurized gaseous phase laser medium. The high voltage discharge electrode (32) is disposed coaxially with the surrounding capacitors (22, 24).

Abstract: A method for rendering a substrate resistant to erosion by a plasma comprising oxygen by providing on the surface of the substrate a layer of a cured polymer of a compound having the formula ##STR1## where: R.sub.1 is selected from the group consisting of:(a) an aliphatic hydrocarbon group containing 2 to 10 carbon atoms, and(b) a group having the formula ##STR2## wherein n=1 to 3 m=0 to 5R.sub.2 and R.sub.2 ' are each selected from the group consisting of an alkyl group containing 1 to 4 carbon atoms, an unsubstituted aryl group, and a substituted aryl group; and R.sub.

Abstract: An imaging sensor for scanning an image in an object space is disclosed. The imaging sensor comprises a first and second plurality of infrared detectors. Also provided is a reflecting means for reflecting a predetermined portion of the object space on the first plurality of infrared detectors during first portion of the scanning cycle. The reflecting means is further able to reflect the predetermined portion of the object space on the second plurality of infrared detectors during the second portion of the scanning cycle. In a further embodiment, the orientation of the detectors permits each of the detectors to be calibrated with respect to another of the detectors by a sequential comparison of the outputs of pairs of the detectors whose fields-of-view overlap.

Abstract: An integrating transimpedance amplifier 10 comprises a differential amplifier constructed of GaAs, MESFET, HEMT, SDHT or MODFET transistors has an input coupled to the output of a radiation detector 12 and an output expressive of the detector signal integrated over a predetermined interval of time. The amplifier has a transistor Q0 coupled to the input for coupling the input periodically to a predetermined voltage potential and a transistor Q.sub.9 coupled to the output of the amplifier for simultaneously periodically coupling the output to a predetermined voltage reference, thereby initializing the amplifier at the beginning of an integration period. A buffer transistor Q.sub.4 couples the output of the amplifier to a GaAs MISFET switch Q.sub.8 which is periodically activated to couple the buffered amplifier output to a storage capacitor Csmp.

Abstract: A directly heated catalyst 10 is comprised of an electrically conductive ceramic substrate 12 having a catalytic coating 14 applied to at least an outer surface thereof. In an illustrative embodiment of the invention the catalytic coating is a noble metal or non-noblemetal coating. In accordance with one embodiment of the invention a high surface area form of platinum (Platinum Black) is deposited upon a ceramic substrate, such as a substrate comprised of SiC or SnO.sub.2. The coating is brought to its activation temperature by resistively heating the substrate with an electrical current. A temperature sensing device (20, 40), such as a thermocouple or a thermostat, may be coupled to the catalyst structure for sensing the temperature of the catalyst to control the heater current supplied to the substrate. The catalyst is shown to be useful for CO.sub.2 gas lasers.

Abstract: A lasing medium (3) and a Raman medium (20) share a common optical cavity. The lasing medium (3) projects laser light into the Raman medium (20) and, when a threshold intensity within the Raman medium is reached, the Raman medium absorbs the laser light and re-radiates coherent light at a shifted frequency. Optical elements within the system provide an optical cavity for the lasing medium and a second cavity for the Raman medium.

Abstract: A flexible epoxy adhesive composition comprising a mixture of a fatty acid modified epoxy resin and an oxypropylene epoxy resin in the ratio of about 1:3 to 1:1. The adhesive paste also includes a stoichiometric amount of a polyamine curing agent, 1 to 20 total liquid weight percent of a plasticizer and 1 to 5 weight percent of microfine silicon dioxide particles. Fillers, such as aluminum oxide and glass beads, are optionally added. This adhesive paste is particularly well suited for use as a flat pack adhesive to provide a releasable bond and is also well suited for use in space applications.

Abstract: Novel processes are provided for synthesizing 2,2-bis(4-fluorophenyl)hexafluoropropane and the use of this synthesized monomer in polymerization reactions to form poly(arylethers) or poly(arylthioethers). Synthesis of 2,2-bis(4-fluorophenyl)hexafluoropropane involves converting the commonly available compound Bisphenol AF to an amino-substituted form, followed by treatment with borofluoric acid and a nitrite, and then an aromatic solvent to obtain the monomer. The monomer can be mixed with either a dihydroxy diphenyl hexafluoropropane or a dimercapto diphenyl hexafluorpropane to cause a nucleophilic substitution reaction, thereby yielding the desired poly(arylether) or poly(arylthioether).

Abstract: Polyimides are prepared from acetylene substituted polyimide oligomers via an addition polymerization reaction which involves homopolymerization. These polymers exhibit low void content when cured and possess superior thermal stability characteristics and physical properties such as structural strength. One of their unique properties is their ability to be processed into useful articles at moderate pressures and temperatures.