The optical fiber preform manufacturing apparatus of the optical fiber preform manufacturing apparat

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PROBLEM TO BE SOLVED : To provide a gas supply nozzle capable of suppressing contamination due to the adhesion of a reaction product to the tip or the mixing of impurities into the core of an optical fiber preform when the preform having added rare earth is manufactured using a MCVD method, and an apparatus for manufacturing the optical fiber preform.SOLUTION : An apparatus for manufacturing an optical fiber preform includes a gas supply nozzle having : a flow passage 14 for a reactive gas 9a and a flow passage 15 for an additive gas 9b formed by concentrically providing an inner side cylindrical part 12 and at least one outer side cylindrical part 13 at an interval by using a heating heater 11 as a central axis; and a tip portion of the inner side cylindrical part 12 projected from that of the outer side cylindrical part 13. A gas supply device has a tapered quartz glass cap at the tip of the inner side cylindrical part 12.SELECTED DRAWING : Figure 3