Highly sensitive micro-curvature sensor based on double-clad polarization-maintaining fiber
摘要
Precise measurement of micro-curvature enables early detection of issues before they reach critical levels, facilitating preventive maintenance and mitigating the risk of significant economic losses and safety hazards. In this paper, we proposed and experimentally demonstrated an innovative sensor for dual parametric simultaneous measurement based on Sagnac-interferometer (SI) constructed by double-clad polarization-maintaining fiber (DPMF). The sensor is designed using a 2 × 2 coupler to connect the DPMF, forming an optical fiber loop structure while granted with a Fiber Bragg granting (FBG). The experiment proves that the SI exhibits curvature sensitivity of − 89.1 nm/m−1 from 0.062 to 0.176 m−1 and − 179.09 nm/m−1 from 0.186 to − 0.26 m−1 while temperature sensitivity of − 1.65 nm/°C. By adding FBG to realize dual parametric simultaneous measurement. The FBG has showed sensitivities of curvature and temperature are − 6.97 nm/m−1 and 0.009 nm/°C. The coefficient matrix approach is employed to simultaneously measure both curvature and temperature. The sensor exhibits ultra-high curvature resolution of 1.1 × 10−4 m−1 and achieves dual-parameter simultaneous measurement for curvature and temperature through a simple fabrication process. Its characteristics of high sensitivity and resolution, low production costs, and straightforward manufacturing make its application prospects in industrial manufacturing and aerospace fields broader.