Patent ID: 9575247
Date: 2017-02-21
CPC Classifications: G02B

Claim:
1. A multimode optical fiber comprising: a core portion extending along an optical axis and doped with GeO a cladding portion provided around an outer periphery she of the core portion and having a refractive index lower than a maximum refractive index of the core portion; and a trench portion provided between the core portion and the cladding portion and having a refractive index lower than the refractive index of the cladding portion, wherein an α value to define a shape of a portion corresponding to the core portion in a refractive index profile in a radial direction of the multimode optical fiber is from 1.9 to 2.2, a maximum relative refractive index difference Δ of the core portion to the cladding portion is from 0.8 to 2.4%, and a diameter of the core portion is from 25 μm to 65 μm, wherein in a cross section of the multimode optical fiber perpendicular to the optical axis, the trench portion in a section of a predetermined length forming at least a part of the multimode optical fiber has a non-circularly symmetric shape with respect to an intersection between the optical axis and the cross section, and wherein in the cross section of the multimode optical fiber, the trench portion has a part where a thickness of the trench portion along the radial direction of the multimode optical fiber is 0.