Low macrobending loss single-mode optical fibre

摘要

A single-mode transmission optical fiber includes a central core region radially outwardly from a centerline to a radius r₁ and having a positive relative refractive index Δ₁; a first inner cladding region extending radially outwardly from the central core to a radius r₂ and having a negative relative refractive index Δ₂; a second inner cladding region extending radially outwardly from the first inner cladding region to a radius r₃ and having a non-negative relative refractive index Δ₃; an intermediate cladding region extending radially outwardly from the second inner cladding region to a radius r₄ having a negative relative refractive index Δ₄ larger in absolute value than the relative refractive index Δ₂; and an outer cladding region extending radially outwardly from the intermediate cladding region and having a non-negative relative refractive index Δ₅; wherein the relative refractive index Δ₂ of the first inner cladding region is −0.1·10⁻³ to −1.0·10⁻³ and the relative refractive index Δ₄ of the intermediate cladding is −3.0·10⁻³ to −5.0·10⁻³.