Abstract: A process is described for making semiconductor devices with highly controlled doping profiles. The process involves minimizing or eliminating segregation effects caused by surface electric fields created by Fermi-level pinning. These electric fields act on dopant ions and cause migration from the original deposition site of the doplant ions. Dopant ions are effectively shielded from the surface electric fields by illumination of the growth surfaces and by background doping. Also, certain crystallographic directions in certain semiconductors do not show Fermi-level pinning and lower growth temperatures retard or eliminate segregation effects. Devices are described which exhibit enhanced characteristics with highly accurate and other very narrow doping profiles.

Abstract: An electroplating process is described for electroplating alloys of palladium and arsenic. The resulting electrodeposits are bright, ductile and remain ductile and crack-free even when the electrodeposits are quite thick. The deposits are quite hard and suitable for contact surfaces particularly in situations where wear characteristics require thick deposits. The electroplating process is also useful for making articles such as bellows by electroform procedures particularly since the electroplated material has extraordinary physical properties (good resilience, low stress and ductility) as well as good corrosion resistance.

Abstract: A quaternary semiconductor diffraction grating, such as an InGaAsP grating suitable for a DFB laser, is embedded in a semiconductor substrate, such as InP. In one embodiment, the grating is fabricated by(1) forming on the top surface of an InP substrate body an epitaxial layer of InGaAsP coated with an epitaxial layer of InP;(2) forming a pattern of apertures penetrating through the layers of InP and InGaAsP; and(3) heating the body to a temperature sufficient to cause a mass transport of InP from the InP epitaxial layer, the thickness of the InP layer being sufficient to bury the entire surface of the InGaAsP layer with InP.

Abstract: A semiconductor epitaxial device structure is described in which there are alternate single crystal layers of semiconductor, insulator and semiconductor. A typical example is InP/CaF.sub.2 /InP. A process for producing such a structure is also described.

Abstract: An integrated photodetector-amplifier is described which is planar and exhibits excellent circuit characteristics including low input capacitance, high speed, and high sensitivity. Also, certain self-alignment features and a planar technology made fabrication of the circuits simpler and easier than most such circuits.

Abstract: Articles are described which utilize a unique photochemical property of a certain class of heterocyclic compounds. These heterocyclic compounds are the mono- and bicyclic aziridines. Oriented crystals of these heterocyclic compounds are photochromic in an unusual way. The effect of the excitation radiation and the strength of the resulting absorption band responsible for the appearance of color depend on the polarization of the radiation. These articles contain at least one optically smooth surface. Typical articles are windshields or glass panes which darken on being exposed to glare and sunglasses. Switching devices are also described which exist in two states; one state characterized by absorption of certain radiation over wavelength range and the other state by high transparency.

Abstract: A procedure is described for drawing glass fibers which are particularly suitable for use in optical waveguides. A laser is used as a souce of heat and an optical system is provided for focusing an annular beam around a glass preform from which the glass fiber is drawn. Particular attention is devoted to the optical focusing system to provide highly uniform distribution of heat and insure very precise short and long term fiber diameter control and precise control of the optical properties (freedom from scattering centers, profile of optical properties across the diameter) of the fiber. Precise diameter control of glass fibers for optical waveguides is highly desirable because it minimizes optical losses and facilitates low-loss splicing of individual glass fibers.

Abstract: Alkaline batteries are described in which a special electrode is incorporated in the positive electrode in order to give added protection against electrochemical damage due to battery reversal. This special electrode contains a hydrogen-absorbing material which also acts as a hydrogen electrode for the conversion of hydrogen ions into elemental hydrogen. Such alkaline batteries are particularly well protected against hydrogen overpressure due to battery reversal with only a small penalty in energy density. Particularly suitable for this application is the use of a hydrogen-absorbing material with nominal formula LnM.sub.5 in which Ln represents a lanthanide metal and M is either cobalt or nickel.

Abstract: A process is described for making nickel cadmium batteries in which the cadmium electrodes for these batteries are electrolytically impregnated under special conditions and employ a particular electrolytic solution. The electrolytic solution contains not only a soluble form of the cation of the active ingredient for the electrode and nitrate ions, but also certain other ions such as chloride, iodide and sulfate ions which increase the rates of impregnation and also increase the electrode loadings. In addition to obtaining more rapid and greater electrode impregnation, the present process improvements facilitate use of a continuous impregnation procedure.

Abstract: Articles are described which utilize a unique photochemical property of a certain class of heterocyclic compounds. These heterocyclic compounds are the mono- and bicyclic aziridines. Oriented crystals of these heterocyclic compounds are photochromic in an unusual way. The effect of the excitation radiation and the strength of the resulting absorption band responsible for the appearance of color depend on the polarization of the radiation. These articles contain at least one optically smooth surface. Typical articles are windshields or glass panes which darken on being exposed to glare and sunglasses. Switching devices are also described which exist in two states; one state characterized by absorption of certain radiation over wavelength range and the other state by high transparency.

Abstract: Devices are described which utilize a low loss dielectric material. This dielectric material is unique in that it combines low dielectric loss with a high and temperature-stable dielectric constant. The material is made up of BaO and TiO.sub.2 and corresponds closely in composition to the compound Ba.sub.2 Ti.sub.9 O.sub.20. Devices utilizing this material are useful at a variety of frequencies, but are particularly advantageous in the microwave region above 0.5 GHz.

Abstract: Electroplating procedures and apparatus are described in which the metal plated out of the bath is replenished by a consumable anode. Particular attention is paid to the design of the anode assembly so as to facilitate rapid replenishment of the consumable part of the anode without introducing electrical resistances which results in nonuniform plating.