MULTIMODE OPTICAL FIBER

摘要

An embodiment of the present invention relates to an MMF with a structure for reducing length dependence of optical characteristics while maintaining bend-insensitivity. The MMF has a trench portion provided between a core portion and a cladding portion and having a refractive index lower than that of the cladding portion. In a cross section of the MMF, the trench portion in at least a partial section of the MMF has a non-circularly symmetric shape with respect to an intersection between the optical axis and the cross section.

主权项

1. A multimode optical fiber comprising:
a core portion extending along an optical axis and doped with GeO2; a first cladding portion provided around an outer periphery 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 first cladding portion and having a refractive index lower than the refractive index of the first 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 first cladding portion is from 0.8 to 2.4%, and a diameter of the core portion is from 25 μm to 65 μm, and 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.