Optical fiber
AssigneeSumitomo Electric Industries, Ltd.
InventorsYoshiaki Tamura, Hirotaka Sakuma, Akiko Funakoshi
Life of this patent
Estimating the term…
Abstract
An optical fiber includes a core, and a cladding. When a refractive index of silica glass is set as n0, a refractive index of the core is set as n1, and a refractive index of the cladding is set as n2, a relative refractive index difference Δ defined by Expression (1): Δ[%]=100×(n12−n22)/2n02 (1) is 0.2% or higher. A ratio of a maximum value of a concentration of the dopant composed of the alkali metal element or the alkaline-earth metal element in the cladding to a maximum value of a concentration of the dopant composed of the alkali metal element or the alkaline-earth metal element in the core is 0.06 or higher and 0.25 or lower.
Claims8
An optical fiber comprising:
- a core;
- and
- a cladding that surrounds the core,
- wherein the core and cladding are respectively formed from silica glass containing a dopant composed of an alkali metal element or an alkaline-earth metal element,
- a relative refractive index difference Δ defined by Expression (1):
- Δ[%]=100×(n12−n22)/2n02 (1)
- is 0.2% or higher, where n0 denotes a refractive index of silica glass that does not contain the dopant, n1 denotes a refractive index of the core, and n2 denotes a refractive index of the cladding, and
- a ratio of a maximum value of a concentration of the alkali metal element or the alkaline-earth metal element in the cladding to a maximum value of a concentration of the alkali metal element or the alkaline-earth metal element in the core is 0.06 or higher and 0.25 or lower.
Dependencies are inferred from the claim text.