| 摘要 |
<p>An optical fiber comprises: a core (1) provided at a center; a first cladding layer (2) provided on a periphery of the core (1); a second cladding layer (3) provided on a periphery of the first cladding layer (2); and a third cladding layer (4) provided on a periphery of the second cladding layer (3), wherein a maximum refractive index of the core is greater than any of maximum refractive indices of the first cladding layer, the second cladding layer, and the third cladding layer, and the maximum refractive index of the second cladding layer is smaller than any of the maximum refractive indices of the first cladding layer and the third cladding layer, a value of a 2 /a 1 is not less than 2.5 and not more than 4.5 when a radius of the core is a 1 and a radius of an outer periphery of the first cladding layer is a 2 , and a relative refractive index difference of the core with respect to a refractive index of the third cladding layer is not less than 0.20 and not more than 0.70%.</p> |
