METHOD FOR PRODUCING OPTICAL FIBER PREFORM, AND OPTICAL FIBER

摘要

Disclosed is a method for producing an optical fiber preform in which a rare earth element is added into the core. The method for producing an optical fiber preform comprises: a step wherein fine glass particles which are mainly composed of silicon dioxide are deposited within a quartz tube by a MCVD method; a step wherein the rare earth element and aluminum are added into the fine glass particles within the quartz tube by an immersion method; a step wherein the quartz tube is heated, while flowing a phosphorus-containing gas into the quartz tube, so that the fine glass particles within the quartz tube are sintered, while having the phosphorus added thereinto; and a step wherein the quartz tube, into which the rare earth element, the aluminum and the phosphorus have been added, is heated and collapsed.