| 摘要 |
PURPOSE:To provide a method for producing a homogeneous, dense and high- quality optical fiber preform. CONSTITUTION:Core/clad ratios in several points along the longitudinal direction of a target member 1 are previously measured to obtain the measured values and weight increase rate of the target member is continually measured during process. The weight increase rate of the target member is controlled within the range of prescribed preferable value by controlling traverse rate of burners 8A, etc., and glass material gas feed amount, based on these measured values and simultaneously preferable glass material gas feed amount previously calculated is fed when the burners comes to a position corresponding to these each point by calculating from core/clad ratio at each point in the longitudinal direction of the target member and core/clad ratio being uniform in the longitudinal direction of the completed preform is realized to provide the objective optical fiber preform having good quality. |
