| 摘要 |
PURPOSE:To improve the breaking strength of the fiber type coupler by incorporating carbon in combustion gas and burning the gas, and forming a carbon film on the surface of the drawn part of a glass member. CONSTITUTION:When a coupler member is formed by fusing and drawing >=2 optical fibers 1 and 2 from which films are removed by a burner 4 which is supplied with the combustion gas to heat the fibers, at least carbon is incorporated in the combustion gas to form the carbon film on the surface of the drawn part of the coupler member. In this case, when the burner 4 is arranged above the drawn part A and a heat-resisting flat plate 5 is arranged opposite the burner 4 by pinching the drawn part A, the temperature of the flame is lowered to suppress wind pressure, thereby adjusting the combustion state. The burner 4 is supplied with the carbon-containing combustion gas and oxidizing gas individually through flow rate valves, etc., so the flow rate can be adjusted individually. Consequently, the breaking strength of the fiber type coupler which deteriorates owing to the presence of a flaw, etc., is increased. |
