Abstract: A method of continuous application of a graded index plastics optical fiber in which the refractive index is highest in the center and decreases progressively towards the periphery, said fiber having a plurality of layers of resin deposited concentrically, the method comprising making a plurality of mixtures, each mixture comprising at least one polymer P and a reactive diluting agent including at least two monomers, then depositing said mixtures in the form of coaxial layers, allowing interdiffusing to take place between the layers, and finally crosslinking the polymer P and/or the reactive diluting agent.

Abstract: An enameling lacquer comprises a base first polymer and a copolymer which is compatible with said first polymer and which contains polymeric chains selected from polysiloxanes, fluorated chains and alkane chains. The lacquer is of particular application to an enameled wire comprising at least one layer of an enamel obtained by reticulation of the lacquer.

Abstract: A polymeric resin for optical fiber strips is formed from a mixture comprising a first base polymer selected from an epoxy acrylate and a urethane acrylate and a copolymer in a proportion of between 0.5% and 20% by weight of said mixture which is compatible with said first polymer and carries polysiloxane chains.

Abstract: A polymer material of the fluorine-containing polyurethane acrylate type for coating an optical fiber or for an optical fiber tape, the material being based on at least a diol, a diisocyanate, and an acrylate, and being characterized by the fact that at least one of the above compounds contains fluorine and that at least one of the above compounds contains sulfur.

Abstract: In a method for determining the physical characteristics of a silicon wafer, one side of the wafer (4) is removably fixed to the base (2) of a container (1) so as to close off a hole (3) therein. An electrical connection to this side of the wafer (4) is made thru the hole (3). The wafer (4) forms the working electrolyte of a cell comprising an electrolyte contained in the container (1). An auxiliary electrode (14) is removably placed in the electrolyte. The method and the device implementing it can be used to determine the crystallographic and electrical characteristics of a sample of silicon.