Abstract: A silica-based optical fiber is provided, which has improved resistance to static fatigue. The fiber includes an outer layer of modified, fused silica which contains zirconia and, optionally, alumina.

Abstract: A GaAs-based self-aligned laser with emission wavelength in the approximate wavelength regime 0.87-1.1 .mu.m is disclosed. The laser is a strained layer QW laser and is readily manufacturable. Preferred embodiments of the inventive laser do not comprise Al-containing semiconductor alloy. Lasers according to the invention can for instance be used advantageously as 0.98 .mu.m pump sources for Er-doped fiber amplifiers.

Abstract: Disclosed is an advantageous method of making ridge-waveguide lasers. The method is a self-aligned method that does not comprise any critical alignment steps. Thus it is useful for making lasers that have a very narrow ridge waveguide. Such lasers are desirable because they can suppress lateral higher order modes.

Abstract: Transition-metal-coated metallic elements, such as electrical contacts, are protected from corrosion by a novel surface treatment. In one embodiment, the treatment involves application of a phosphonate solution, optionally preceded by application of a chromatic solution phosphonate.

Abstract: A silicon MOSFET is provided, which can be made with an effective channel length of under one micrometer without incurring severe short-channel effects. The MOSFET includes first and second channel regions located between the source and drain regions, the first channel region overlaying the second channel region. The second channel region has a higher carrier density than the first channel region, and functions as a buried ground plane.

Abstract: An active optical device comprises a glass, waveguiding structure disposed on a substantially planar principal surface of a substrate. The structure includes a silica-based, erbium-doped active core. The active core has an erbium-to-silicon atomic ratio of at least about 0.01, an absolute erbium concentration of at least about 1.4.times.10.sup.20 atoms per cubic centimeter, and a radiative lifetime of the erbium lasing level of at least about 7 milliseconds. Also disclosed is a method for forming an active optical device, including the step of depositing an erbium-doped active core by sputtering.

Abstract: It has been discovered that co-doping of Er-doped Si with a light element such as C, N or F can result in substantially increased Er luminescence. A further increase in luminescence can result if, in addition, oxygen is present in the Si. Apparatus or systems according to the invention comprise a device (e.g., laser, optical ampifier, LED) that comprises a planar waveguide whose core region contains, in addition to at least 90 atomic % Si or SiGe alloy, Er, Pr and/or Nd, and further contains C, N and/or F, and preferably also contains oxygen. Currently preferred apparatus or systems according to the invention comprise means for electrically pumping the waveguide means.

Abstract: Disclosed is a method of making a semiconductor device that exemplarily comprises depositing a Ti/Pt layer onto a AuBe intermediate layer on a p-doped region of a semiconductor body. It also comprises depositing a Ti/Pt layer onto a n-doped region of the semiconductor body, or onto a AuGe intermediate layer on the n-doped region, followed by rapid thermal processing. Exemplarily, the device is a semiconductor laser, the n-doped region is InP, the p-doped region is InGaAs or InGaAsP, and RTP involves heating in the range 425.degree.-500.degree. C. for 10-100 seconds. The method comprises fewer processing steps than typical prior art methods, reduces the danger of fabrication error and of wafer breakage and, significantly, results in contacts that can be relatively thermally stable and can have very low specific contact resistance (exemplarily as low as 10.sup.-7 .OMEGA..multidot.cm.sup.2).

Abstract: Disclosed is a broadly applicable method for making an article that, exemplarily comprises a superconductive oxide body, including a thin layer on a substrate, or powder particles. In a preferred embodiment, the method comprises forming a precursor melt and contacting at least a part of the melt with oxygen such that the concentration of oxygen in the part of the melt increase to a critical concentration, resulting in formation of the desired oxide, substantially without drop in temperature. The precursor melt comprises at least one metallic element M, and at least the part of the melt is at a temperature T, with T.sub.m <T<T.sub.o, where T.sub.m is the freezing temperature of the melt and T.sub.o is the melting temperature of the superconductive oxide. In an exemplary embodiment the melt consists essentially of Yb, Ba, and Cu in 1:2:3 atomic ratio, T is about 900.degree. C. A layer of superconductive oxide on a Sr-TiO.sub.3 substrate is formed by dipping the hot (900.degree. C.

Abstract: An optical fiber connector pair is provided, which includes a plug assembly and a receptacle. An optical connection can be repeatedly made and broken by insertion and withdrawal, repectively, of the plug assembly relative to the receptacle. The final alignment of the mating fiber ends is provided by a pair of silicon blocks, each having a guiding groove formed in one surface. One block is included in the receptacle, and the other block is included in the plug assembly. One fiber end is affixed in each groove. The act of inserting the plug assembly in the receptacle brings the grooved surfaces together such that each fiber is captured by the opposing groove.

Abstract: Disclosed is an edge-emitting semiconductor laser that has a single waveguiding structure, and that comprises means for reducing the transverse divergence of the far-field pattern of the laser emission. Typically these means comprise reflecting means (preferably transverse distributed Bragg reflectors) disposed parallel to the junction plane of the laser. Lasers according to the invention can have a highly stable single mode output having a substantially symmetrical far field pattern. Disclosed is also an advantageous method of making ridge-waveguide lasers that can, inter alia, be used to make lasers according to the invention. The method is a self-aligned method that does not comprise any critical alignment steps. Thus it is useful for making lasers that have a very narrow ridge waveguide. Such lasers are desirable because they can suppress lateral higher order modes.

Abstract: To attain high strength optical glass fibers, the glass preforms, from which the fibers are drawn, must generally be free of surface imperfections such as bubbles, and air lines. It has been discovered that these imperfections can be removed quickly and cleanly by contacting the preform surface with a substantial portion of the electrically conducting plasma region (the plasma fireball) extending from a plasma torch. Significantly, the surface material is substantially removed by vaporization, due to the extremely high plasma temperature (>9000.degree. C. at the plasma center) of the isothermal plasma torch. Though the temperatures in the tail of the plasma fireball are substantially less than at the plasma center, the temperatures are generally still several thousand degrees centigrade.

Abstract: A novel method of producing mixed metal oxide powder (e.g., ferrite powder, or high temperature superconductor powder such as YBa.sub.2 Cu.sub.3 O.sub.x powder) is disclosed. The method comprises forming an intimate mixture of appropriate metal salts (e.g., nitrates and acetates), at least one of which is an oxidizing agent with respect to at least one of the others, and heating the mixture to a reaction temperature such that an exothermic redox reaction occurs. Appropriate choice of oxidizing and reducing agents permits control of heat of reaction and reaction temperature. The product of the reaction typically is a precursor of the desired mixed oxide, the precursor typically consisting essentially of the metal constituents of the mixed oxide and oxygen. Heat treatment in an O.sub.2 -containing atmosphere transforms the precursor into the desired mixed oxide powder. The thus produced powder can then be used in conventional fashion, e.g., to produce bodies therefrom by pressing and/or sintering.

Abstract: Disclosed is a novel "hermetic" optical assembly. A radiation-transmissive member seals an aperture in the assembly housing. The member comprises two major surfaces and a recess that extends from one surface towards the other, with a "septum" between the bottom of the recess and the other surface. An optical or opto-electronic device typically is mounted on the inside surface of the member, and the end of an optical fiber is maintained outside of the assembly in coupling relationship with the device. In a currently preferred embodiment the recess extends from the outward-facing surface of the member and serves to position the end of the optical fiber with respect to a device mounted in a "well" in the inward-facing surface of the member. In another embodiment, the outward facing surface of the member comprises geometrical features (e.g., recesses) that mate with corresponding features (e.g.

Abstract: Disclosed is a time division multiplexed optical communication system that is capable of operation at relatively high bit rates and that is relatively stable and immune to crosstalk and noise. The system comprises receiver means wherein the timing signal for demultiplexing is derived from the fully multiplexed optical pulse stream by means that comprise a narrow band receiver and timing means that produce a lower-frequency timing signal from the output of the narrow band receiver. The timing signal is used to drive one or more optical switches. In one embodiment of the invention the receiver means have a binary-tree architecture and the timing signals are substantially sinusoidal. In another embodiment the receiver means have a linear-bus architecture and the timing signals are pulse-like.

Abstract: Disclosed is a method for making a solder joint without flux, in the presence of an inert gas. A pair of articles having solder-coated surfaces are heated to melt the solder, pressure is applied to the joint region, and the articles are cooled. During the heating step, inert gas is flowed over the articles.

Abstract: The TVS method is a voltammetric method for detecting mobile ionic impurities in the dielectric layer of a MOS capacitor structure. Disclosed here is a method of semiconductor device fabrication involving a modified TVS method in which the voltage is changed in discrete steps rather than varied continuously, and charge, rather than induced current, is measured. The modified TVS method can be faster than conventional TVS, and calibration is unnecessary.

Abstract: The presence of oval defects on MBE-grown compound semiconductor (e.g., GaAs, InP, or InGaAs) epitaxial layers has proven to be a serious obstacle to the use of such material for the manufacture of integrated circuits (ICs), even though the use of such material potentially could result in ICs having superior performance. One particularly prevalent type of oval defect is generally referred to as .alpha.-type. It has now been discovered that compound semiconductor epitaxial layers that are essentially free of .alpha.-type oval defects can be grown by MBE if first at least a portion of the Ga and/or In metal crucible is coated with an appropriate second metal. The second metal is chosen from the group of metals that are wetted by the first metal and that are less electronegative than the first metal. Aluminum is a currently preferred second metal.

Abstract: A method of producing normal-metal-clad superconductive oxide wire, tape and the like is disclosed. The method comprises forming an intermediate body by surrounding a quantity of the oxide powder (e.g., Ba.sub.2 YCu.sub.3 O.sub.6.9) with an appropriate normal metal jacket, reducing the cross section of the intermediate body by any appropriate technique (e.g., drawing or rolling), and heat treating the elongated body such that substantial sintering of the powder results, and such that, after completion of the heat treatment, the sintered oxide has a composition that is associated with superconductivity in unclad bulk samples of the oxide. The latter condition requires that at least the portion of the cladding that is in contact with the oxide powder is substantially inert with respect to oxygen and the oxide under the conditions of the heat treatment. Silver is the currently preferred inert normal metal. Exemplarily, Ag can be used to provide a diffusion barrier with other normal metal (e.g.

Abstract: Disclosed is a method for removing poly-para-xylylene, its derivatives, and copolymers (collectively called "parylene") from bodies, including relatively large bodies such as printed circuit (PC) boards, that is capable of yielding relatively high removal rates. A body such as a PC board coated with parylene is placed into a reaction chamber downstream from a microwave plasma such that plasma discharge products generated by the microwave plasma react with the parylene, etching the parylene without exposing the body to bombardment by energetic ions and/or electrons. The plasma is generated from a gas mixture containing oxygen, a second gas, and optional additives such as N.sub.2 O, He,or Ar. The second gas is selected from the group consisting of fluorocarbons, fluorosulfides, and chlorofluorocarbons. A currently preferred second gas is CFR.sub.4. The inventive method is also applicable for fabricating articles such as integrated circuits and semiconductor devices that comprise a parylene layer.