| 摘要 |
An optical fiber of the invention satisfies Δcore>Δic>Δtmax>Δtmin, −0.15%≧Δtmax>Δtmin≧−0.7%, and 0.45≦(rtmax−rin)/(rout−rin)≦0.9 where the relative refractive index difference of the core is Δcore, the relative refractive index difference of the internal cladding coat is Δic, the relative refractive index difference of a highest refractive index layer in the trench coating is Δtmax, the relative refractive index difference of a lowest refractive index layer in the trench coating is Δtmin, the radius of an internal edge of the trench coating is rin, the radius of an external edge of the trench coating is rout, and the radius of an internal edge of a highest refractive index layer in the trench coating is rtmax and where the relative refractive index differences are based on a refractive index of the outermost cladding coat. |
| 主权项 |
1. An optical fiber, comprising:
a core provided at a central portion; an internal cladding coat provided around the core, having a refractive index less than a refractive index of the core; a trench coating provided at a periphery of the internal cladding coat and constituted of two or more layers having different refractive indices; and an outermost cladding coat provided at a periphery of the trench coating, wherein a layer having the highest refractive index in the trench coating configures an outermost layer of the trench coating, Δcore>Δic>Δtmax>Δtmin, −0.15%≧Δtmax>Δtmin≧−0.7%, and0.45≦(rtmax−rin)/(rout−rin)≦0.9 are satisfied where a relative refractive index difference of the core is represented as Δcore, a relative refractive index difference of the internal cladding coat is represented as Δic, a relative refractive index difference of a layer having the highest refractive index in the trench coating is represented as Δtmax, a relative refractive index difference of a layer having the lowest refractive index in the trench coating is represented as Δtmin, a radius of an internal edge of the trench coating is represented as rin, a radius of an external edge of the trench coating is represented as rout, and a radius of an internal edge of a layer having the highest refractive index in the trench coating is represented as rtmax and where the relative refractive index differences are based on a refractive index of the outermost cladding coat. |
