| 摘要 |
PROBLEM TO BE SOLVED: To obtain a plastic optical fiber cable with which thermal contraction is suppressed. SOLUTION: A preform is obtained by forming a core part having a GI type refractive index profile in a hollow cylindrical clad pipe. A GI type POF can be obtained by heating/fusion-drawing the preform. A GI type core wire 16 is obtained by covering the outer circumferential face of the GI type POF with polyethylene to form a protective layer 123. The GI type core wire 16 is arranged with a large number of aramid fibers on the outer circumference and covered with polyvinyl chloride to form the outermost layer 125, so that the plastic optical fiber cable 20 is obtained. The aramid fibers become a loose-type coating buffer layer 124, relaxing a stress imparted radially to the optical fiber cable 20. The optical fiber cable 20 is annealed at 60°C for 17 hours. Since the polymer of the outermost layer 124 is reoriented, longitudinal contraction is suppressed in the optical fiber cable 20 even when heat is applied thereto. COPYRIGHT: (C)2006,JPO&NCIPI |
