Patent ID: 7702205
Filing Date: 2010-04-20
Classification: G02B

Abstract:
1. An optical fiber made of silica-based glass, comprising: a center core region containing germanium having a first refractive index; an outer core layer containing fluorine having a second refractive index formed on an outer circumference of the center core region; and a cladding layer made of pure silica glass having a third refractive index formed on an outer circumference of the outer core layer, wherein the second refractive index is lower than the first refractive index, the third refractive index is higher than the second refractive index and lower than the first refractive index, a maximum relative refractive index difference Δ a relative refractive index difference Δ a ratio of the relative refractive index difference Δ a diameter a of the center core region is 9.0 micrometers to 10.5 micrometers, a ratio a/b of the diameter a of the center core region to a diameter b of the outer core layer is 0.20 to 0.35, and optical characteristics of the optical fiber show that