Optical fiber and method of manufacturing optical fiber
AssigneeSumitomo Electric Industries, Ltd.
InventorsTetsuya NAKANISHI, Masaaki HIRANO, Tetsuya HARUNA, Maki IKECHI
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Abstract
An optical fiber having excellent strength that can be manufactured at low cost, as well as a method for making such optical fiber, is provided. An optical fiber 1 is a silica-based optical fiber comprising a core 11, an optical cladding 12 surrounding the core & 11, and a jacketing region 13 surrounding the optical cladding 12 and having a uniform composition throughout from the internal circumference to the outer circumference. A compressive strained layer having a residual compressive stress is provided at the outermost circumference of the jacketing region 13.
Claims9
1-7. (canceled)
A method of manufacturing an optical fiber, comprising. a fiber drawing step wherein a glass filament having a desired outer diameter is formed by heating and fusing one end of a silica-based optical fiber preform including a core, an optical cladding surrounding the core, and a jacketing region surrounding the optical cladding;
- and a stress imparting step wherein the outer circumferential portion of the glass filament is re-heated with a stress imparting unit to a temperature higher than a glass transition point after the temperature of the whole glass filament formed in the fiber drawing step has become lower than the glass transition point, and thereby a compressive strained layer is formed at the outermost circumferential portion of the jacketing region.
Dependencies are inferred from the claim text.