| 摘要 |
PROBLEM TO BE SOLVED: To provide a process for efficiently producing a porous glass preform by adjusting the gas discharge of a stage for depositing glass particulates in a process for producing the glass preform for optical fibers by a VAD method and an apparatus for production therefor. SOLUTION: This process for producing the glass preform for optical fibers comprises depositing a target on the glass particulates synthesized in the flames of burners. The amts. of the respective gases of respective burners are gradually decreased by decreasing displacement in the initial period of production. The displacement is thereafter gradually increased and nearly the specified displacement is maintained at the stationary time. The apparatus for production consists of the burners 1, 2, a pressure tap 3, a discharge pipe 4, a chamber 5, a target rod 6 and a displacement control valve 8. |
