19-ring-air-core fiber supporting thousands of OAM modes for spatial division multiplexing

We propose and design a 19-ring-air-core fiber that can support about 3000 orbital angular momentum (OAM) modes (156 modes in each ring) with <-80 dB inter-ring cross talk across the entire C and L bands after 100-km fiber propagation. Moreover, the eigenmodes are all separated from their adjacent modes by effective index differences >2.67 x 10(-4) and mode groups by > 1.90 x 10(-2), which can guarantee the stable transmission of OAM modes. This designed fiber is a potential candidate for applications in spatial division multiplexing (SDM) of optical channels to improve the capacity of next-generation high-speed optical communication systems, especially in short-distance applications. In this Letter, we also show the relationship between supported OAM mode numbers, total cross talk, and effective refractive index of intra-ring modes during the optimization of fiber through numerical simulations. It can provide a related reference for the future design of multi-ring-core fibers. (C) 2022 Optica Publishing Group

Automated summary

In this letter, we propose and design a 19-ring air-core fiber that can support approximately 3000 orbital angular momentum (OAM) modes. The fiber exhibits low inter-ring cross talk and high stability, making it suitable for spatial division multiplexing (SDM) in next-generation high-speed optical communication systems.