Abstract: An optical device for use as an optical filter or modulator comprises an optical waveguide including a portion having a refractive index that varies with optical intensity and a mechanism for providing and directing at least two coherent waves at that portion such that a standing wave of a modulated refractive index is established by interference between the coherent waves. The standing wave provides a temporary modulated index grating in the waveguide.

Abstract: An optical fibre transmission line is installed by first installing a conduit having one or more bores and subsequently inserting flexible, lightweight optical fibre members containing the optical fibres into the bores.The optical fibre members are propelled by employing the fluid drag of air, or another suitable gas, passed at high velocity through the bores.

Abstract: A sheath for optical fibres comprises a compound sheath having an inner sheath (41) of high modulus and density, and an outer sheath layer (42) of low density material. The outer sheath layer may be of foamed polyethylene and the inner sheath of polypropylene, both conveniently formed by extrusion.

Abstract: An optical fibre transmission line is installed by first installing a conduit having one or more bores and subsequently inserting flexible, lightweight optical fibre members containing the optical fibres into the bores.The optical fibre members are propelled by employing the fluid drag of air, or another suitable gas, passed at high velocity through the bores.

Abstract: Aqueous solutions of aminomethylenephosphonic acid, chiefly diethylenetriaminepenta(methylenephosphonic acid), are disclosed containing a crystallization inhibitor which is an alkali-metal salt of an organic carboxylic acid and residual hydrochloric acid originating from the manufacturing process. The equivalent molar concentration ratio of carboxylic acid salt to hydrochloric acid is greater than 1, preferably from 1.5 to 3.

Abstract: A plurality of articles are advanced in continuous sequence in spaced relation to each other through an electroplating bath to pass in sliding engagement with a pair of lands, thereby to move selected, laterally-extending strips of the articles along an anode surface located between the lands in selected, closely spaced, facing relation to the anode surface. Jets of the electroplating solution are directed through a plurality of openings in the anode surface to provide a continuous positive flow of electroplating solution in a direction from the anode surface against the selected strips of the articles moving past the anode surface and to permit the flow of electroplating solution to pass between the articles while the lands substantially restrict the flow of the electroplating solution in other directions. Electrical current is directed through the flowing electroplating solution between the anode surface and the article strips for plating the selected article strips to a desired thickness.

Abstract: A process for plating beryllium copper with an excellent electrically conductive material such as gold for use in high reliability applications wherein a heat treating step is employed after forming to yield a desired hardness spring temper comprising the steps of: providing a copper-rich surface on the beryllium copper; electroplating the copper-rich surface with a diffusion barrier preplate; heat treating the beryllium copper material to a desired temper; and electroplating the material with a high electrically conductive material. This process provides for a void-free, durable gold plate which can be produced by a continuous automated strip plating line before and after heat treating.