| 摘要 |
PURPOSE:To manufacture a glass base material for a wide-zone optical fiber with high reproducibility by a vapor phase axial deposition (VAD) method by periodically changing the distance between the deposition center of glass fine particles and burner. CONSTITUTION:Oxyhydrogen burner 14 is supported by supporting shaft 17 at distaness L from axis so that the radiating direction to disklike starting member 11 which is turned on shaft 12 makes angle theta to axis. Starting materials for manufacturing glass introduced into burner 14 are hydrolyzed by flame 16, and the resulting glass particles are sprayed to grow porous glass body 13 by a VAD method while pulling up member 11. In said method, the form glass body 13 burner 14 is moved back and forth in the arrow 19 direction with moving unit 18 from distance Lo where coefft. alpha of refractive index distribution of a formed glass fiber is made 2. Burner 14 is preferably moved by about + or -1-+ or -3mm. distance. |
