| 摘要 |
PURPOSE:Cooling devices are provided before and after the heater and glass for optical fiber is deposited on the inner surface of a cylindrical glass tube, thus increasing uniformly the amount of soot deposited to form title material with long effective length because of its increased uniformity in the lengthwise direction. CONSTITUTION:Local heater 2 is reciprocated several times on cylindrical glass tube 1 to deposite desired glass soot on the inner surface of glass tube 1. Coolers 41 and 42 are equipped immediately before and after heater 2 respectively to cool the glass tube 1, thus depositing uniformly soot, that is, fine particles formed by the gas phase reaction in the tube 1 and increasing the uniformity of the parent maerial for optical fiber in the lengthwise direction. Further, the yield of the starting materials is increased and the deformation of glass tube 1 is reduced, thus giving the material for optical fiber with high accuracy in the core diameter. |
