| 摘要 |
PURPOSE:To obtain a high-quality optical fiber preform prevented in the generation of residual strains and bubble by depositing a porous glass fine particle layer at the tip of a starting member with clad burners, while the clad burners are controlled so that the highest temperature of the surface temperature distribution is controlled in a prescribed range. CONSTITUTION:A rod-like porous glass fine particle product 10 comprising the quartz glass of GeO2, etc., and used for the core of the optical fiber is allowed to grow with a burner 1 for the core. A glass-producing raw material is fed into side burners 2, 3, 4 to form a glass fine particle layer 20 comprising SiO2 and giving the clad of the optical fiber around the fine particle product 10 to produce the optical fiber preform. Therein, the surface constant temperature line of the layer 20 formed with burners 2, 3, 4 is controlled to be the line X, and the surface temperature distribution of the layer 20 is controlled within the range of the highest temperature to the highest temperature X 55% wherein the highest temperature is approximately 600 deg.C and the lowest temperature is approximately 330 deg.C. |
