Zhang Cong, Shen Lei
Appl Opt. 2021 Sep 20;60(27):8480-8484. doi: 10.1364/AO.435477.
An all-fiber mode power splitter (MPS) for mode-division multiplexing (MDM) transmission is proposed and numerically investigated. The MPS is based on the configuration of the symmetric few-mode fiber (FMF) coupler, with the operation of four modes (, , , and ). By comprehensively optimizing the FMF coupling parameters, including both the coupling area distance and the coupling length , MPSs with various power splitting ratios from 90%:10% to 50%:50% under the condition of different single guided mode injection are obtained. Then, the MPS with a 90%:10% power splitting ratio under the simultaneous injection of , , , and modes is reported, which can be used as the mode tap for the optical performance monitoring. Moreover, based on the proposed MPS structure, selective mode power strippers with more than 25 dB mode extinction ratio for , , , and modes are numerically verified. The arbitrary single guided mode arising in the FMF can be selectively coupled into another FMF, together with an insertion loss of less than 1 dB. Owing to the flexible setting of the mode power splitting ratio, the proposed MPS may become a potential solution to realizing system performance monitoring and mode power routing in MDM systems.
提出并对一种用于模分复用（MDM）传输的全光纤模式功率分配器（MPS）进行了数值研究。该MPS基于对称少模光纤（FMF）耦合器的结构，工作于四种模式（、、、）。通过综合优化FMF耦合参数，包括耦合面积距离和耦合长度，在不同单导模注入条件下获得了功率分配比从90%:10%到50%:50%的各种MPS。然后，报道了在同时注入、、、模式下功率分配比为90%:10%的MPS，其可作为光学性能监测的模式抽头。此外，基于所提出的MPS结构，对模式消光比大于25 dB的、、、模式的选择性模式功率剥离器进行了数值验证。FMF中出现的任意单导模可被选择性地耦合到另一根FMF中，插入损耗小于1 dB。由于模式功率分配比的灵活设置，所提出的MPS可能成为实现MDM系统中系统性能监测和模式功率路由的潜在解决方案。
