| 摘要 |
PROBLEM TO BE SOLVED: To provide a primary coated optical fiber keeping the transmission loss of an optical fiber stable over a long term without causing a situation that a bare optical fiber and a primary coating layer are partially peeled on a boundary even when the optical fiber is immersed in water for a long time. SOLUTION: When it is assumed that the adhesive force of primary coating material under ordinary temperature and ordinary humidity is f<SB>0</SB>and the adhesive force thereof after immersing it in 60°C warm water for two days is f<SB>1</SB>in the optical fiber obtained by coating the outer peripheral surface of the bare optical fiber with the primary coating layer and a secondary coating layer in order, the optical fiber satisfies relation being 0.7≤f<SB>1</SB>/f<SB>0</SB>or dispersion in 1550nm wavelength is 2 to 10 ps/nm/km, a dispersion slope is≤0.13 ps/nm<SP>2</SP>/km, A<SB>eff</SB>is≥50μm<SP>2</SP>, and the transmission loss is≤0.25 dB/km, and the increase of the transmission loss after immersing it in the 60°C warm water for 30 days is≤0.01 dB/km in 1550nm wavelength. COPYRIGHT: (C)2004,JPO |
