| 摘要 |
PURPOSE:To prevent infiltration of moisture in a cable and to obviate increase of a transmission loss by airtightly covering the circumference of optical fibers, fibers or optical fiber tape fibers with metal foil. CONSTITUTION:An optical fiber unit is constituted by aggregating plural pieces of the optical fibers 1 or fibers and covering the circumference thereof with the metallic foil 4. The metallic foil 4 is preferably about 10-100mum thick to prevent impairment of the flexibility as the unit. The material thereof is exemplified by Cu, Ni, Sn, etc., as these materials have the lower tendency to ionization and by Al, etc., as these materials inhibit corrosion by forming oxide films. The infiltration of moisture and hydrogen into the inside is thereby prevented without impairing the flexibility and the deterioration of the mechanical strength thereof and the increase in the transmission loss are suppressed. |
