| 摘要 |
A method and apparatus for overcladding an optical fiber preform rod are provided to prevent the influx of exterior air into an interface of the optical fiber preform rod and a glass tube upon overcladding and to facilitate the collapse of the glass tube. The method for overcladding an optical fiber preform rod comprises the steps of: placing the optical fiber preform rod(10) into a glass tube(30); heating a surface of the glass tube(30) while injecting a purging gas into a clearance between preform rod(10) and the glass tube(30), so that the glass tube(30) and the preform rod(10) are initially bonded, wherein the purging gas is effused therefrom to prevent the influx of foreign matters; determining a change in pressure or a variation in flow rate of the purging gas; and stopping the supply of purging gas according to determined data to form lower negative pressure inside the glass tube(30), so that the closing of the optical fiber preform rod(10) and the glass tube(30) is completed. |
