PRODUCTION OF FIBER FOR OPTICAL COMMUNICATION

摘要

PURPOSE:To reduce the refractive index drop portion of the fiber without impairing the advantages of a flame hydrolysis method by specifying the production process of the parent material. CONSTITUTION:A glass fine powder sintered body 12 having a specified dopant concentration distribution is formed on a starting member 10 by a flame hydrolysis external deposition method to obtain a hollow transparent glass body 14, after which this is made to the transparent glass body of solid type. It is then elongated to a slender transparent glass body rod 160, by which the refractive index drop portion 180 created in the central part is reduced relatively. Next, a glass fine powder sintered body 20 for core 200 having such a dopant concentration distribution at which the refractive index decreases continuously and a glass fine powder sintered body 22 for clad 220 of a constant refractive index are subsequently formed on the slender transparent glass body rod 160, after which the rod is converted to transparent glass to obtain a parent material 24. This is then spun to obtain the fiber.