| 摘要 |
PURPOSE:To improve the thermal characteristics by using a transparent amorphous polymer as a core material, a transparent polymer having a refractive index lower than the refractive index of the core material as a clad material and a resin curable by UV as a sheath material. CONSTITUTION:An optical fiber of a plastic has 3-layered construction of a core, clad and sheath. Polystyrene, polymethyl methacrylate, polycarbonate or the like which is a transparent amorphous polymer is used as the core material. A transparent polymer having a refractive index lower than the refractive index of the core material, for example, a polymer of a styrene deriv. wherein a fluorine atom is substituted with a hydrogen atom, a methacrylate deriv. or the like is used as the clad material. An epoxy acrylate resin or the like which is a resin curable by UV is used as the sheath material. Even if the optical fiber made of such materials is put in a high temp. state of >=120 deg.C and <170 deg.C, the fiber is free from a decrease in the optical transmission characteristics owing to thermal shrinkage and deformation and the thermal characteristics of the optical fiber of the plastic is improved. |
