Optical fiber

Abstract

In order to decrease transmission loss caused by Rayleigh scattering in an optical fiber, without negatively affecting the curvature loss, provided is an optical fiber comprising a core at a center thereof, a low refractive index layer that is adjacent to the core and covers an outer circumference of the core, and a cladding that is adjacent to the low refractive index layer and covers an outer circumference of the low refractive index layer, wherein a refractive index of the core is higher than a refractive index of the cladding, a refractive index of the low refractive index layer is lower than the refractive index of the cladding, and the refractive index of the low refractive index layer decreases in a direction from an inner portion of the low refractive index layer to an outer portion of the low refractive index layer.

Dependencies are inferred from the claim text.