| 摘要 |
PURPOSE:To produce a titled fiber having stable performance with good reproducibility by disposing >=4 pieces of oxyhydrogen burners which rotate at the same period on the outside periphery of a glass, rod, feeding gaseous SiCl4 to the burners and adding gaseous GeCl4 and BBr3 to >=2 pieces of the burners. CONSTITUTION:Oxyhydrogen burners 2, 3 which rotate at the same period as the period of a quartz glass rod 1 consisting of a core are disposed around the rod 1, and gaseous SiCl4 is fed to the burners 2, 3 to deposit fine particles of SiO2 on the outside circumferential surface of the rod 1 by flame hydrolysis reaction. GeCl4 and BBr3 are added and the mixture thereof is fed to >=2 pieces of the burners 3 placed to face to each other to deposit GeO and B2O3 together with SiO2 on the outside circumferential surface of the rod 1. A porous blank material of a circular preform consisting of the layer deposited with pure quartz and the doped quartz layer is thus formed. Such blank material is heated to about 1,600 deg.C to vitrify the deposited layer thereby forming a transparent base material. Said base material is further drawn and spun at about >= 2,000 deg.C, whereby the optical fiber of a single mode for retaining the plane of polarization is obtd. |
