| 摘要 |
PURPOSE:To control freely the refractive index of a base material for an optical fiber when gaseous starting materials are blown on a target rod from a burner to form the base material, by irradiating laser light on a frame contg. the gaseous starting materials in the lateral direction and by monitoring the coefft. of correlation between detected signals of scattered light. CONSTITUTION:GeCl4 and SiCl4 as gaseous starting materials and gases such as Ar, O2 and H2 are blown on the tip of a target rod 2 from a burner 1 in the form of a flame 3 to deposit soot on the tip of the rod 2 while slowly pulling up the rod 2 at a velocity (v), and the deposited soot is made transparent to form a base material for an optical fiber. At this time, laser light 4a is irradiated on the flame 3 between the tip of the soot and the burner 1 from a light source 4, scattered light 5 making an angle theta to the laser light 4a is detected with a photodetector 6, and the base material is manufactured while monitoring the coefft. of correlation between the detected signals with a correlation meter 7. The refractive index of the base material for an optical fiber can be easily controlled. |
