Production method for optical fiber base material, and optical fiber base material
AssigneeSumitomo Electric Industries, Ltd.
InventorsHirotaka Sakuma, Yuki Kawaguchi
Life of this patent
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Abstract
A method for manufacturing an optical fiber preform made of silica-based glass, the method including: forming a core portion; and forming a cladding portion surrounding the core portion, the cladding portion having a refractive index lower than a refractive index of the core portion, wherein the forming the core portion includes: adding an alkali element group consisting of an alkali metal element and an alkaline earth metal element to an inner surface of a glass pipe made of silica-based glass; and integrating the glass pipe and a glass rod disposed inside the glass pipe to form an integrated rod after the adding.
Claims12
A method for manufacturing an optical fiber preform made of silica-based glass, the method comprising:
- forming a core portion;
- and
- forming a cladding portion that has a refractive index lower than a refractive index of the core portion and surrounds the core portion,
- wherein the forming the core portion comprises:
- adding an alkali element group including an alkali metal element and an alkaline earth metal element to an inner surface of a glass pipe made of silica-based glass;
- integrating the glass pipe and a glass rod disposed inside the glass pipe to form an integrated rod after the adding;
- and
- applying a glass layer around the integrated rod, the glass layer having a refractive index higher than that of the cladding portion,
- wherein a mean value of a mass fraction of chlorine in the glass layer is 100 ppm or greater and 2000 ppm or less.
Dependencies are inferred from the claim text.