Patent ID: 11899237
Assignee: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
Field: Optics (Instruments)
Classification: CPC G  H | IPC G

Claim 6:
7. The multicore optical fiber according to claim 1, wherein
a ratio a2/a1 between the a1 and the a2 is 1.0 or more and 3.0 or less,
a relationship between the Δ1, the a2/a1, and an effective cross-sectional area Aeff at a wavelength of 1550 nm satisfies Formula C4 and
a relationship between the Δ2, the a2/a1, and the Aeff satisfies Formula C5,

[Formula C4]

Δ1≤(1.9×10−6Aeff2−0.00033Aeff+0.0163)a2/a1+(−8.0×10−6Aeff2+0.00139Aeff−0.0705)  (C4)

[Formula C5]

Δ2≥(5.0×10−8Aeff2−6.5×10−6Aeff−0.00108)a2/a1+(−2.9×10−7Aeff2+5.58×10−5Aeff−0.00594)

and

Δ2≤(5.0×10−7Aeff2−9.5×10−5Aeff+0.0056)a2/a1+(−1.6×10−6Aeff2+0.00031Aeff−0.0208)  (C5).