Method for manufacturing a silica porous material, a method of manufacturing an optical fiber preform, porous silica, and the optical fiber preform

摘要

Production of silica porous material comprising a; deposition depositing soot layers on the outer peripheral surface of the optical fiber core rod by the burners of the plurality; disposing a plurality of burners around the optical fiber core rod The method, in the deposition process, ^and, x (g / cm 3), the deposition thickness of the average bulk density, each of said soot layer is formed by one of the burners of the plurality soot layer each of the plurality of when it is a (mm) y is a, was filled with ^{2 -3.8x} + 1.3 0.1 ≦ y ≦ 4.0x and 0.2 ≦ x ≦ 0.5, the maximum bulk density of the soot layer of the multiple I deposited value so as to have 0.6g / cm ³ or less.