| 摘要 |
PURPOSE:To improve the transmission characteristic of an optical fiber by using an angular and a duplex flame burner respectively to form core soot and clad soot, and specifying the setting angle of the angular burner and Ar flow rate. CONSTITUTION:The angular burner 1 is provided to form core soot, and two flame burners 2 and 3 are furnished to form clad soot. Central layers 6, 7, and 8 for respectively supplying a gaseous glass material, gaseous Ar, and gaseous H2, the second layer 9 for gaseous H2, the third layer 9 for gaseous Ar, and the fourth layer 10 for gaseous oxygen are arranged in the angular burner 1. In this case, the setting angle theta of the burner 1 to the horizontal direction is controlled to 35-40 deg., and the flow rate of gaseous Ar to the central layer 7 to 0.6-0.8l/min. Since the angle theta of the burner 1 and flow rate of gaseous Ar to the central layer are thus made appropriate, the diameter of core soot is reduced. Accordingly, the transmission characteristic of the optical fiber is improved. |
