| 摘要 |
PURPOSE:To uniformize the diameter of an optical fiber by inserting a preform fixed to a supporting rod into an evacuated furnace core tube, heating and melting the lower end, and drawing an optical fiber. CONSTITUTION:The upper end of the supporting rod 2 fixing the preform 1 is held by a chuck 7, and the chuck 7 is fixed to the slider 9 fixed to a threaded shaft 10 through an arm 8. The supporting rod 2 is passed through a guide pipe 31, and inserted into a furnace core tube 3 wherein plural cavities 33 are formed by partition plates 32, the inside of the furnace core tube 3 is kept at about 0.1Torr by a vacuum pump 60, then a heater 4 is energizing to heat and melt the lower end of the preform 1, and an optical fiber is drawn. |
