| 摘要 |
PROBLEM TO BE SOLVED: To provide an apparatus for producing a porous glass base material (preform) for optical fiber which can stably produce a porous glass base material for optical fiber having high quality. SOLUTION: In a VAD method, porous glass fine particles are deposited on a target bar 4 to grow a glass fine particle sediment for optical fiber. In this process, the target bar 4 is only supported with a chuck 26 in a freely rotatable manner without raising it, the tip of a soot body 2 is detected with a laser beam 36 and an optical receiver 38, and a core burner 20 and a clad burner 22 are descended. While the burners are descended under synchronization with the tip position detecting apparatus, glass fine particles are deposited on the lower part of the porous glass, and the glass fine particle sediment for optical fiber is grown. |
