Curvature sensor based on cascaded dual-core photonic crystal fiber

In recent years, as the development of aerospace, road bridge, precisioninstrument and other fields, the requirements of curved detection have become more and more precise and multi-point, and the advantages of fiber curvature sensors have become increasingly obvious. Based on the principle of mode interference, we proposed a cascade single-mode fiber, few-mode fiber and dual-core photonic crystal fiber curvature sensor, which can measure the distribution curvature, and solve the problem of measurement of multiple points that cannot be measured using one sensor. The experiment results show that within 0 to 1.06m−1 curvature range, each test point curvature sensitivity and linearity are −1.58 nm/m−1 and 0.98135, −1.62 nm/m−1 and 0.99504, −1.56 nm/m−1 and 0.98301, −1.74 nm/m−1 and 0.99701, and −1.31 nm/m−1 and 0.97315, respectively.