METHOD OF AND APPARATUS FOR PRODUCING OPTICAL FIBRE PREFORMS

摘要

Preforms for the formation of optical fibres having a controlled radial refractive index profile are produced by the cold deposition onto a cylindrical support of the solid reaction products of fluids selected and proportioned to be vitrifiable to a glass whose refractive index varies according to proportioning of the fluids, the deposited preform then being treated to remove its water content and vitrified. The deposition is achieved by directing the fluids through nozzles in a controlled atmosphere chamber towards either an inner or an outer surface of the cylindrical surface, the nozzles and the cylindrical surface being relatively translated and rotated during deposition to form successive layers of reaction products on the cylindrical surface.