Large-scale dual-ring optical fiber sensing system with self-healing capability against natural disasters

Long-range fiber sensor systems have matured, enabling stable and accurate remote sensing. However, as monitoring often occurs in harsh environments, ensuring the reliability and robustness of signal transmission requires a resilient self-healing mechanism. To address this, this study proposes a large-scale dual-ring optical fiber sensing system capable of multi-breakpoint protection. The proposed architecture facilitates the dynamic insertion and removal of sensing nodes and enables the sharing of optical fiber links. This approach effectively reduces the complexity and cost associated with deploying dedicated backup fiber links. Unlike typical dual-ring systems that require complex mechanisms to provide two virtual backup loops, the proposed architecture offers three virtual backup loops for each node using only two 2 × 2 optical switches in a remote node. Consequently, this simplified architecture significantly enhances system practicality. Experimental results demonstrate that the system possesses robust self-healing capabilities, successfully retrieving signals from remote nodes even under three simultaneous fiber link failures.