| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for producing an optical fiber preform and an apparatus for use in the method capable of accurately controlling a refractive index of a clad and a deposition volume of glass fine particles. SOLUTION: In a chamber 2, while a core glass rod 6 for the optical fiber preform is rotationally moved by a rotating chuck 5 with the axis of the rotation in the stretching direction of the core glass rod 6 and traversed by a support member 3 in the stretching direction, flame is blown from a burner 4 to the outer peripheral surface of the core glass rod 6 to deposit glass fine particles 8 to form an optical fiber porous preform. Temperature measuring means (9A and 9B) are provided in a plurality of locations in the chamber 2 such as a first position higher than the core glass rod 6 and a second position lower than the core glass rod 6 to measure temperatures to control the volume of supply air depending on the results in temperatures measured. Alternatively, the outer diameter of the porous preform (soot preform) is measured with a laser displacement gauge 10 to control the deposition volume of the glass fine particles. |
