High spectral-efficiency, ultra-low MIMO SDM transmission over a field-deployed multi-core OAM fiber

作者：Junyi Liu, Shuqi Mo, Zengquan Xu, Yuming Huang, Yining Huang, Zhenhua Li, Yuying Guo, Lei Shen, Shuo Xu, Ran Gao, Cheng Du, Qian Feng, Jie Luo, Jie Liu, Siyuan Yu · 发表于：Photonics Research · 年份：2024 · DOI：10.1364/prj.533993 · 被引用次数：7 · 研究领域：Optical Network Technologies、Advanced Fiber Optic Sensors、Advanced Photonic Communication Systems

Space-division multiplexing (SDM) systems based on few-mode multi-core fibers (FM-MCFs) utilize both spatial channels (fiber cores) and modes (optical modes per core) to maximize transmission capacity. Unlike laboratory FM-MCFs or field-deployed single-mode multi-core fibers (SM-MCFs), SDM transmissions over field-deployed FM-MCFs in outdoor settings have not been reported. Therefore, concerns remain that environmental interference and cabling stress could worsen inter-core and intra-core modal crosstalk and impact the performance of SDM systems over FM-MCFs. In this paper, we demonstrate successful bidirectional SDM transmission over a 5-km, field-deployed seven ring-core fiber (7-RCF) with a cladding diameter of 178 μm. Our measurements show no significant differences in attenuation and mode coupling compared to pre-cabling conditions, confirming the fiber’s resilience to environmental disturbances and adaptability to cable deployment. Using the field-deployed 7-RCF, bi-directional SDM transmission is implemented, achieving spectral efficiency (SE) of 2×201.6 bit/(s Hz) which sets a new record in field-deployed fiber cables that is a tenfold increase over previous systems. Furthermore, these results were achieved using a small-scale 4×4 multiple-input multiple-output (MIMO) scheme with a time-domain equalization (TDE) tap number not exceeding 15. These results demonstrate the substantial potential of using SDM techniques to significantly enhance SE and expand capacity in pr...