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.

Abstract: The present invention relates to a method for producing a preform, which is substantially free of OH impurities, for an optical fiber, wherein one or more quartz layers, which may or may not be doped, are deposited on the internal surface of a quartz glass support tube, in which method a furnace is moved axially with respect to the support tube, and after the quartz layers have been deposited the support tube is contracted into a bar-shaped preform while being heated, wherein the furnace comprises an electrical resistance furnace, in which furnace the support tube is rotated, with the space between the rotating support tube and the furnace being washed with an inert gas.

Abstract: The present invention relates to a method for producing a perform, which is substantially free of PH impurities, for an optical fibre, wherein one or more quartz layers, which may or may not be doped, are deposited on the internal surface of a quartz glass support tube, in which method a furnace is move axially with respect to the support tube, and after the quartz layers have been deposited the support tube is contracted into a bar-shaped perform while being heated, wherein the furnace comprises an electrical resistance furnace, in which furnace the support tube is rotated, with the space between the rotating support tube and the furnace being washed with an inert gas.

Abstract: The invention relates to a device for manufacturing a preform, wherein a carrier tube is collapsed to a preform, which device comprises a heating element forming a cylindrical envelope, which envelope defines an annular inlet opening and an annular outlet opening at opposite ends of the envelope, a carrier tube being present within the cylindrical envelope, between said openings, the heating element being movable in axial direction with respect to the carrier tube, and means for supplying a non-oxidizing gas to the space between the carrier tube and the envelope.

Abstract: The invention relates to a device for manufacturing a preform, wherein a carrier tube is collapsed to a preform, which device comprises a heating element forming a cylindrical envelope, which envelope defines an annular inlet opening and an annular outlet opening at opposite ends of the envelope, a carrier tube being present within the cylindrical envelope, between said openings, the heating element being movable in axial direction with respect to the carrier tube, and means for supplying a non-oxidizing gas to the space between the carrier tube and the envelope.

Abstract: The present invention relates to a rod-shaped preform for manufacturing an optical fibre 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 fibre, 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 fibre therefrom.