| 摘要 |
Provided is a method of manufacturing an optical fiber base material that enables an optical fiber to be obtained having a trench-type refractive index distribution, low transmission loss, low connection loss with respect to standard single-mode optical fiber, and good flexibility. A method of manufacturing an optical fiber base material having at least four layers including a core, a first cladding, a second cladding containing fluorine, and a third cladding comprises preparing a starting base material that includes the core and the first cladding; forming a porous intermediate glass base material by supplying glass raw material and oxygen to a high-frequency induction thermal plasma torch to synthesize glass fine particles that are then deposited on a surface of the starting base material; forming an intermediate glass base material that includes the core, the first cladding, and the second cladding containing fluorine, by heating and vitrifying the porous intermediate glass base material in an atmosphere containing fluorine; and providing the third cladding on the outer surface of the intermediate glass base material. |
