| 摘要 |
PURPOSE:To heighten accuracy of removal and obtain image fiber that can transmit picture of good quality by removing a jacket by a chemical method. CONSTITUTION:Plural glass rods 3 for optical fiber are filled in a jacket tube 4 and melt them together by heating. A unit fiber preform thus obtained is covered by the jacket on outer periphery, and this jacket is dissolved out by acid before drawing. The jacket can be dissolved out and removed uniformly and completely by adjusting the kind of acid, concentration, temperature, time etc. For instance, relation between the time of HF immersion and the depth of quartz dissolved out is determined beforehand, and the jacket can be dissolved and removed completely by adjusting the time of immersion. The preform from which the jacket is removed is elongated by heating to form unit fiber. Then, plural unit fibers are bundled and melted and elongated by heating, and desired image fiber is obtained. |
