| 摘要 |
PURPOSE:To smooth the fusion of a side surface and to prevent the increase of a loss caused by the imperfect fusion by vibrating an optical fiber by ultrasonic wave at least until the fusion of the side surface is finished. CONSTITUTION:Heating of the optical fibers 20 and 22 by a burner 18 is started by previously actuating a light source device 24 and an ultrasonic wave generator 30. Then, when tensile force is added to the fibers 20 and 22 by actuating fine adjustable stages 14 and 16 by delaying timing a little, the side surface of a part softened by the heating is fused and the stretch thereof is started. In accordance with it, light which is made incident only on a light receiving device 26 is also made incident on a light receiving device 28 by coupling. Then, in the case that the branching ratio of 50% is obtained, for example, the burner 18 and the fine adjustable stages 14 and 16 are stopped when the respective light receiving levels become equal. At such a time, the ultrasonic wave is impressed until the optical coupling is started. |
