Alcatel

Silitec Fibers Sa

Silitec Sa

Rosendahl Nextrom Gmbh

Carlos Pedrido

Olivier Schuepbach

Philippe Roy

Bernard Leuenberger

Frédéric Sandoz

Philippe Ribaux

Philippe Hamel

Peter Othenin

Methiew Devautour

The present invention relates to a method and an apparatus for fabricating a preform () that can be used for drawing an active optical fiber (). The present invention further relates to an active optical fiber (), designed for amplification or attenuation purposes, drawn from said preform () and to an optical amplifier () using a laser active optical fiber.

Method for fabricating an optical fiber preform

The method for fabricating an optical fiber comprises the steps of inserting a primary optical fiber preform () having a first primary axis (x) and an outer surface () into an overcladding tube () having a second primary axis (x) and an inner surface (), so that said outer surface and inner surface define an interior space (); holding the primary preform () in a centrally inserted position within the overcladding tube () with said first and second primary axes (x, x) in substantial alignment with each other; supplying overcladding grain () into the interior space () that is limited at the lower end of the overcladding tube () by means of a closure (); generating a condition of reduced pressure within the interior space () that is limited at the upper end of the overcladding tube () by means of an adjoiner (), which holds the primary optical fiber preform () and the overcladding tube () in position; and heating the unprocessed secondary preform (), that consists of the primary preform (), the overcladding tube () and the overcladding grain (), at its lower end to a softened state and simultaneously or subsequently drawing an optical fiber therefrom.

Method for fabricating an optical fiber, preform for fabricating an optical fiber, optical fiber and apparatus

An inlet arrangement for inserting a preform () into a furnace () for drawing a fiber (). The furnace includes an enclosure () at the top of which there are both an opening to allow insertion of a preform which moves in translation, and a preform inlet arrangement (). The inlet arrangement comprises both an injector () situated at the level of the opening to inject inert gas around the preform and to fill the enclosure, and at least one seal (B) fixed above the injector and designed to allow the preform to pass therethrough, with its cylindrical main body () being surrounded. The inlet arrangement further comprises an airlock () for closing and sealing the top of the furnace, above the injector, whether a preform is present or absent, which airlock is pressurized to prevent the surrounding air entering. The rods of the equipped preforms carry respective continuity tubes () of the same diameter as the bodies.

Preform inlet arrangement for an optical fiber drawing furnace, a furnace provided with that kind of inlet arrangement, and a preform equipped to co-operate with that inlet arrangement

An apparatus for curing a photocurable coating provided on a fiber, includes an irradiator tube having an upstream end on which an injection assembly is provided, and a downstream end on which an exhaust assembly is provided. The injection assembly receives an inert gas flow. The injection assembly includes a diffuser that splits the inert gas flow into a counter flow and a tube flow. The counter flow is directed counter to the travel direction of the fiber, and the tube flow is directed in a laminar fashion through the irradiator tube. The exhaust assembly has a vent though which the tube flow is drawn, and an air opening provided between a downstream end of the irradiator tube and the exhaust vent.

Apparatus and method for curing a photocurable coating provided on a fiber

Method for curing a photocurable coating provided on a fiber

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Boudry, Switzerland

Carlos Pedrido