Abstract:
The present invention relates to a method of applying glass layers, which may or may not be doped, to the interior of a substrate tube by means of a chemical vapor deposition (CVD) technique, using a reactive gas mixture, in order to obtain a preform that exhibits a precisely defined refractive index profile, which method comprises a number of steps.
Abstract:
The invention relates to an access network for exchanging communication signals between a transit network and at least one communication medium of a user. The communication medium is operatively connected to an exchange by means of an optical fibre connection for exchanging the communication signals, and the exchange is connected to the transit network. The fibre connection comprises at least one multimode fibre, which is bent over at least one first part of its length, in such a manner that the fibre comprises at least one complete winding in the first part thereof mainly for maintaining one or more modes of the communication signals into the fibre. Said modes have been selected from a group comprising the ground mode and one or more lower modes near the ground mode.
Abstract:
The invention relates to a method of applying a protective organic coating to an optical glass fiber, said glass fiber is drawn from a preform and passed through a liquid which contains the material for forming said organic coating, once the amount of liquid coating material to be applied to the fiber has been adjusted, said coating matrial is hardened, while a gas is passed along the liquid wherein nitrous oxide (an N2O-containing gas) is used as said gas. The invention also relates to the coated optical glass fiber, produced by that method.
Abstract:
The present invention relates to a rod-shaped preform for manufacturing an optical fiber therefrom, as well as to a method for manufacturing such a rod-shaped preform. The present invention furthermore relates to a method for manufacturing an optical fiber, wherein one end of a rod-shaped preform is subjected to a heat treatment, after which the thus softened end of the rod-shaped preform is subjected to a pulling force for the purpose of drawing an optical fiber therefrom.
Abstract:
The invention relates to an access network for exchanging communication signals between a transit network and at least one communication medium of a user. The communication medium is operatively connected to an exchange by means of an optical fiber connection for exchanging the communication signals, and the exchange is connected to the transit network. The fiber connection comprises at least one multimode fiber, which is bent over at least one first part of its length, in such a manner that the fiber comprises at least one complete winding in the first part thereof mainly for maintaining one or more modes of the communication signals into the fiber. Said modes have been selected from a group comprising the ground mode and one or more lower modes near the ground mode.
Abstract:
The present invention relates to a method and a device for manufacturing optical performs, in which one or more layers of glass, doped or undoped, are deposited onto the internal surface of a hollow substrate tube, which deposition is effected by supplying one or more reactive gas mixtures of glass-forming compounds tot the interior of the hollow substrate tube and subsequently generating a non-isothermal plasma in the hollow substrate tube, after which the preform is subjected to a contraction process for the purpose of forming a massive rod, from which optical fibres are drawn.