FURNACE FOR COATING ON OPTICAL FIBER

摘要

PURPOSE:To provide a titled furnace which can form a film having no defects and pinholes on a fiber without the undesirable deposition of particles on the fiber by providing a gas isolation chamber and liquid isolation chamber to prohibit the introduction of a circumferential medium into a reaction chamber. CONSTITUTION:The optical fiber 20 is online drawn out through a CVD furnace in such a manner that the fiber is protected by the film deposited by evaporation thereon. The fiber 20 is introduced through the gas isolation chamber 26 in which an inert gas is filled into the reaction chamber 21. The greater part of the chamber 21 is filled with a vacuum bottle 213 forming a cylindrical channel 214 around the fiber 20. The diameter of the channel 214 is as small as about 3mm; therefore, a reactive gas passes near the fiber 20 and reacts efficiently with the fiber. The fiber 20 on which the film is formed is taken out through the liquid isolation chamber 27. The introduction of the circumferential medium into the chamber 21 according to the movement of the fiber 20 into said chamber is prohibited by the provision of the gas isolation chamber 26 and the liquid isolation chamber 27, by which the undesirable particles deposited on the fiber are removed and the film having no defects and pinholes is formed.