| 摘要 |
PURPOSE:To obtain an optical fiber which is suitably used at high temperatures without any decrease in light transmissivity by coating an optical fiber element wire with metal, and bending it forcibly and maintaining the residual deforma tion state. CONSTITUTION:This optical fiber is formed by coating the optical fiber element wire 1 with a metallic film 2, and has a finite radius of curvature. Further, the optical fiber element wire is made of an orpiment-based inorganic material, but coated with the metal by a plating method, a chemical vapor-depositing method, etc. The metal deforms plastically when loaded above its yield point although the fiber element wire itself never deforms plastically, so the metal is bent forcibly to deform until plastic deformation is caused except by thermal bending and then released, so that stress remains. Consequently, the stress is balanced in the composite body of the optical fiber element wire and metal- coating film and the specific radius of curvature is maintained. |
