| 摘要 |
PURPOSE:To remarkably improve the characteristics of low temperature loss of optical fiber strands by reducing the coefficient of linear expansion of a plastic pipe in which the optical fiber strands are stored by a thermoplastic plastic layer reinforced by fibers applied to the plastic pipe. CONSTITUTION:An optical cable 10 forms a unit code 18 consisting of a plastic pipe 14 in which plural optical fiber strands 12 are loosely stored and a thermoplastic plastic layer 16 reinforced by fiber extruded so as to be applied to the surface of the pipe 14. It is preferable to adhere the plastic pipe 14 to the plastic layer 16. Each optical fiber strand 12 is composed of a protective primary coat formed on an optical fiber and a buffer layer. Since with a low melting point is used for the plastic layer 16 mixed with glass fiber, the inside plastic pipe 14 is not deformed at the extrusion molding and the total equivalent linear expansion coefficient between the plastic pipe 14 and the plastic layer 16 is reduced. |
