Low-cross-talk and multi-channel heterogeneous 13-core four-LP mode fiber with a high refractive index ring and a trench

We propose a heterogeneous 13-core few-mode fiber, which is characterized by the combination of a high refractive index ring and a trench. All cores of the optical fiber can stably transmit L P 01 , L P 11 , L P 21 , and L P 02 modes in the C + L band through structural optimization and numerical analysis. The effective refractive index difference of the L P 21 and L P 02 modes reaches 2 × 10 − 3 , which is conducive to the independent transmission of modes. The trench can effectively suppress the inter-core cross talk below − 50 d B / k m at 1550 nm. The proposed few-mode multi-core fiber is conducive to solving the long-distance signal transmission problem of large capacity and low cross talk in future optical communication systems.