Bending-insensitive multimode optical fiber and bending-insensitive multimode optical fiber system

摘要

PROBLEM TO BE SOLVED: To provide a bending-insensitive multimode optical fiber in which both securing of frequency gain and reduction of loss due to bending are achieved in a high frequency region. SOLUTION: A core region 1 having a graded index type profile, an inner clad region 2 surrounding the core region, a trench region 3 surrounding the inner clad region, and an outer clad region 4 surrounding the trench region are provided. In the multimode optical fiber, the refractive indexes of the inner clad region and the outer clad region are the same, and the specific refractive index difference Δ2 [%] between the refractive index and the refractive index of the trench region and the radial width of the inner clad region It has a positive linear relationship with Wcl, and the relationship between the target trench region size Vtr (target) and the specific refractive index difference Δ2 is (201.8 × (Δ2) 2-16.3 × Δ2 + 451.7. ) ≤ Vtr (target) ≤ (201.8 × (Δ2) 2-16.3. × Δ2 + 451.7) × (1.05) [μm2%]. [Selection diagram] Fig. 1