A novel few-mode multi-core fiber with large effective mode area and low inter-core crosstalk

This paper proposes a novel 7-core 5-mode fiber with large mode area and low inter-core crosstalk(XT). The proposed optical fiber, by adopting a combination of air-trench structure and high-index ring, realizes large mode area and low XT. The numerical analyses reveal that the proposed fiber can stably transmit 5 LP modes in the C+L band; the effective mode area of each of the 5 LP modes is larger than 110 µm2; the XT of in each of the 5 LP modes is smaller than −79 dB/km; each mode has an effective refractive index difference bigger than 1.1 × 10−3. Therefore, a low XT result can still be achieved when the mode area is large. The proposed optical fiber may be well utilized to construct a high-capacity fiber optic transmission system.