Abstract: The disclosed method of making a mixed glass optical fiber exemplarily comprises providing a high-silica tube, and causing molten non-high silica glass to flow into the bore of the tube by application of a pressure differential. In order to prevent cracking, the tube desirably has an outer diameter/inner diameter ratio of at least 5, preferably about 10 or even more, and an inner diameter of at most 1 min. In a preferred embodiment, a conventional SiO.sub.2 tube is partially collapsed to an inner diameter less than 1 mm, a quantity of a non-high-silica glass is placed in a neck of the partially collapsed tube and heated such that molten glass communicates with the reduced-diameter portion of the bore and can be drawn into the reduced-diameter portion by means of a vacuum. The resulting mixed glass body is then further stretched to result in a core rod of core diameter at most 0.3 min. After overcladding the core rod with SiO.sub.2, fiber is drawn from the thus produced preform. A thus produced fiber with SiO.

Abstract: Described is a novel packaging of MCM tiles without wire-bond interconnections and in a total thickness which is reduced relative to conventional MCM packaging. The MCM tile includes a substrate with a plurality of peripheral metallizations and at least one chip flip-chip mounted on the substrate. The PWB is provided with an aperture which is smaller than the size of the silicon substrate but larger than the outside dimensions of the mounted chips. The substrate is positioned on the PWB so that its ends overlap areas of the PWB adjacent the aperture and the chips fit into the aperture. Peripheral metallizations on the substrate are interconnected to metallizations on the PWB by either solder reflow technology or conductive adhesive technology.

Abstract: We have discovered that hydrogen-related loss in silica-based single mode transmission optical fiber can be reduced or eliminated by use of a substrate tube that contains hydrogen getter sites. Exemplarily, substrate tubes according to the invention are doped with Ge or P.

Abstract: An optoelectronic lII-V or II-VI semiconductor device comprises a thin film coating with optical characteristics providing low midgap interface state density. A field effect device for inversion channel applications on III-V semiconductors also comprises a thin dielectric film providing required interface characteristics. The thin film is also applicable to passivation of states on exposed surfaces of electronic III-V devices. The thin film comprises a uniform, homogeneous, dense, stoichiometric gallium oxide (Ga.sub.2 O.sub.3) dielectric thin film, fabricated by electron-beam evaporation of a single crystal, high purity Gd.sub.3 Ga.sub.5 O.sub.12 complex compound on semiconductor substrates kept at temperatures ranging from 40.degree. to 370.degree. C. and at background pressures at or above 1.times.10.sup.-10 Torr.

Abstract: Described is a plastic encapsulated electronic device having an integrated circuit unit, a lead frame and a plastic material encapsulating the IC unit and portions of the leads into a sealed package. Each of the leads includes an inner portion adjacent the IC unit, an outer portion laying in a different plane than the inner portion, and a central portion interconnecting the inner and the outer portions. The plastic enclosure is so formed that the outer portion of each lead, except for its lowermost flat surface and a short outermost section, is embedded in the plastic material. The bottom surface of the plastic enclosure is substantially coplanar with the lowermost flat surface of each lead. The short outermost portion of the outer lead portion extends beyond the plastic material for testing purposes. This arrangement provides for a robust encapsulation of the leads avoiding the prior problems of the prior art.

Abstract: Electronic devices having at least two components wire mating contact pads are provided with high-aspect-ratio solder joints between the mating pads. These joints ar formed by placing a composite solder medium containing solder wires in an electrically insulating matrix such that at least two solder wires are in contact with the mating pads, and fusing the wires to the pads. The insulating matrix with remainder of solder wires is then optionally removed from between the said at least two component. The composite solder medium is formed by preparing an elongated body of solder wires in an insulating matrix and cutting off slices of the composite solder medium, the solder wires having a high-aspect-ratio of length to the diameter. Alternatively sheets of the composite solder medium are prepared by magnetically aligning solder coated magnetic particles into columns arranged transverse of an insulating matrix and heating sufficiently to fuse the solder in each column into a continuously conducting solder path.

Abstract: Multilayer circuit devices include a plurality of metallized patterns thereon, said patterns being separated by a polymeric dielectric film. The various metallized patterns are interconnected by means of microvias through the polymeric film or films. Each of the metallizations is a composite including in succession from the substrate or from the polymeric film, a layer of titanium (Ti), a layer of titanium and palladium alloy (Ti/Pd), a layer of copper (Cu), and a layer of titanium and palladium alloy (Ti/Pd). The Ti--Ti/Pd--Cu--Ti/Pd composite is hereinafter referred to as TCT. The adhesion between the polymeric film and the top Ti/Pd layer is better than that between the polymer and gold (Au) and comparable to that between the polymer and an adhesion promoted Au layer. Use of the TCT metallization also results in additional cost reduction due to the elimination of Ni and Au layers on top of the Cu layer.

Abstract: Disclosed is a method of fabricating a stoichiometric gallium oxide (Ga.sub.2 O.sub.3) thin film with dielectric properties on at least a portion of a semiconducting, insulating or metallic substrate. The method comprises electron-beam evaporation of single crystal, high purity Gd.sub.3 Ga.sub.5 O.sub.12 complex compound combining relatively ionic oxide, such as Gd.sub.2 O.sub.3, with the more covalent oxide Ga.sub.2 O.sub.3 such as to deposit a uniform, homogeneous, dense Ga.sub.2 O.sub.3 thin film with dielectric properties on a variety of said substrates, the semiconducting substrates including III-V and II-VI compound semiconductors.

Abstract: A multilayer composite interconnection for use in circuits including thin film elements and electrical interconnections includes a copper barrier layer interposed between a nickel layer and a gold layer of the interconnection. The copper layer is in a thickness sufficient to bar or at least to restrict diffusion of nickel through the gold layer under processing and operating conditions. The interconnection multilayer composite interconnection includes in an ascending order, titanium, palladium or palladium-titanium alloy, copper, nickel, copper barrier and gold layers.

Abstract: A voltage controlled ring oscillator whose frequency does not depend on the number of stages in the ring oscillator. The inventive voltage controlled ring oscillator comprises N inverters connected in series with the output of the Nth inverter being coupled into the input of the first inverter. The output of each inverter is connected to a transconductance amplifier. The outputs of all transconductance amplifiers are summed. The oscillation period of the circuit is 2t.sub.d, (where t.sub.d is the delay of one inverter) which is independent of the number of inverters in the ring oscillator.

Abstract: A process for detecting arc discharges in power cables connecting power supply board and at least one equipment rack, the power supply board including circuit breakers operable at a preset current level, said arc discharge occurring at a fraction of said current level. After the arc discharge is detected, a signal representing the presence of the arc discharge is supplied to a power supply control, and a control signal is provided by the power supply control to cause said at least one circuit breaker to open interrupting supply of power to an affected power cable.

Abstract: A new electro-optic sampling probe with femtosecond resolution suitable for ultra-fast electro-optic sampling. The new probe is several times thinner and has a dielectric constant four times less than the best reported conventional bulk LiTaO.sub.3 probes. In addition, the ultimate bandwidth is 50 percent greater than an equivalent LiTaO.sub.3 probe. The probe is a thin film of Al.sub.x Ga.sub.1-x As used in both total internally reflecting and free-standing geometries. Here x is chosen for sufficient transmission of the crystal to the wavelength of the laser source being used for electro-optic sampling. The thickness of the film is a small fraction of the thickness of prior art probes and is chosen, for speed and sensitivity of electro-optic sampling, to be thin compared to the spatial extent of the laser pulse. The thin film probe eliminates many of the problems associated with the use of bulk crystals as electro-optic sensors.

Abstract: This invention embodies a method and apparatus for determination of surface resistivity (.rho.) of materials to be used for a desired purpose. The surface resistivity is obtained by measuring surface resistance (R) of at least one square area of the material, and converting the surface resistance into a surface resistivity (.rho.) by a correction factor K (K=.rho./R) whenever the total area of the material is greater than three square area. The surface resistance is measured by placing a pair of square electrodes, spaced from each other a distance equal to the side of the square, applying measuring voltage potential to the electrodes, and determining the surface resistance of said at least one square area. The surface resistivity of materials of any size can be obtained by multiplying the surface resistance value by a correction factor determined for the size of the material being investigated.

Abstract: A solder paste is composed of a vehicle (or flux) system and a mixture of at least two solder powders. One component of this mixture is a eutectic or near-eutectic Sn/Pb alloy powder, while the other component comprises powders selected from at least one elemental metal powder or at least one solder alloy powder or at least one elemental metal powder and at least one solder alloy powder. Said other component is a powder or combination of powders each of which has a liquidus temperature which is lower by at least 5 degrees Centigrade (.degree.C.) than the solidus temperature of said eutectic or near-eutectic Sn/Pb alloy powder or a solidus temperature which is higher by at least 5.degree. C. than the liquidus temperature of said eutectic or near-eutectic Sn/Pb alloy powder. The eutectic or near-eutectic Sn/Pb powder makes up from 5 to 95 weight percent of the total powder mixture. Alternatively, not all powders which comprise the second component need to obey this rule so long as at least 30% by wt.

Abstract: An electroless process has been developed to deposit nickel and gold onto optical fibers using aqueous chemistry. The key to the process is a sensitization of a surface of an optical fiber using a dilute aqueous stannous fluoride solution in absence of oxygen. Stannous fluoride solution is prepared by dissolving crystalline SnF.sub.2 in deionized water. Subsequent treatment includes immersion of sensitized optical fiber in a palladium chloride/HCl aqueous solution and commercially available electroless nickel and electroless gold solutions. The process is compatible with either chemical or fusion lensing operations by using a strippable polymer coating to selectively metallize near the fiber end. The solder joints to the metallized fiber are hermetic as determined by helium leak testing, and solder pull-test strengths typically range from 3-5 pounds, depending on the type of solder.

Abstract: A cyanide based aqueous solution for stripping palladium from copper-containing substrate. The solution includes a cyanide radical source compound, Na.sub.2 CO.sub.3, a nitrobenzoic acid, NaOH, thallium compound, an organo mercapto compound, and water. The presence of the organo mercapto compound in thallium containing cyanide bath permits efficient stripping of palladium from copper containing substrates with minimum corrosion damage to the substrate.

Abstract: Described is a new method and apparatus for measuring the thickness of a thin conductive coating deposited on a moving elongated dielectric body. Of special use is an application of a carbon coating on an optical fiber. The thickness of the conductive coating is measured by establishing an electromagnetic field in a resonator including an elongated unshielded helix and a pair of coupling loops. The helix is suspended between the coupling loops out of contact with either one of them. An electromagnetic energy is coupled into one loop as an input signal from a source of electromagnetic energy and coupled out from the other loop as an output signal. The difference between the magnitude of energy of an empty helix or of a helix with an uncoated body, and the helix with a coated body, is used for controlling the coating process.

Abstract: A process of batch assembly of sundry leaded or padded devices, encapsulated and non-encapsulated, onto a printed wiring board (PWB), which exhibit significant improvements in both manufacturability and reliability. A pressure frame assembly apparatus permits an application of uniformly distributed pressures to a variety of leaded packages and padded semiconductor chips during cure of conductive adhesives (AdCons), and leads to the reduction of variations in initial interconnection resistance, and thereby to the enhancement of the reliability of AdCon interconnections. The pressures are applied to the devices by an external application of a fluid under pressure to a flexible, resiliently stretchable membrane which conformably envelops outlines of the devices and adjacent areas of the PWB.

Abstract: Absorption properties of an optically active medium can be changed drastically by a Fabry-Perot microcavity. Optically active medium of the cavity includes a host material which is not optically active and at least one rare earth ion which provides optical activity to the medium. The Fabry-Perot cavity is designed to be resonant with excitation wavelength of an absorption band of the host material. The excitation is provided by a source of radiation positioned such that the radiation impinges on the cavity at an angle within a range of from zero to less than 90 degrees from the normal to the top surface of the cavity. In one embodiment Er-implanted SiO.sub.2 is used as the optically active medium. SiO.sub.2 :Er has an absorption band at 980 nm and an emission band at 1.55 .mu.m due to 4f intra-atomic transitions of Er.sup.3+ ions. The Fabry-Perot cavity is designed to be resonant with the 980 nm absorption band of SiO.sub.2 :Er.

Abstract: This invention embodies single mirror light-emitting diodes (LEDs) with enhanced intensity. The LEDs are Group III-V and/or II-IV compound semiconductor structures with a single metallic mirror. The enhanced intensity is obtained by placing an active region of the LED having from two to ten, preferably from four to eight, quantum wells at an anti-node of the optical node of the device created by a nearby metallic mirror. Such multiquantum well LED structures exhibit enhanced efficiencies approaching that of a perfect isotropic emitter.