| 摘要 |
PURPOSE:To improve the mechanical strength by using heat sources which contain no carbon and have temperature gradients having an enough high temperature area to fuse an optical fiber and an enough low temperature area to smooth the optical fiber surface. CONSTITUTION:When >=2 optical fibers 3a and 3b whose jackets are removed are fused and drawn to form a coupler member, the heat sources 1 and 2 which contain no carbon and have the temperature gradients having the enough high temperature area for fusing the optical fibers and the enough low temperature area to smooth the optical fiber surfaces are used to fuse and drawn the fibers. In this case, an electric resistance heater which has a temperature distribution of a high temperature part and a low temperature part or a burner which does not contain carbon and heats the fiber by being supplied with combustion gas is usable. Consequently, a recessed part is prevented from being formed on the surfaces of the fibers 3 and the mechanical strength of the fiber type coupler is improved. |
