Abstract We have demonstrated a high-sensitivity Fabry-Perot curvature sensor. The main components of its sensing fiber are hollow silica tube and single-mode fiber (SMF). When the sensor is bent, the length of the FPI changes with curvature. Hereby, we can achieve vector curvature measurement through cavity length demodulation. The convex and concave bending sensitivities are 151.30 nm/m−1 and −333.89 nm/m−1, respectively. Besides, the curvature sensitivity is optimized with the increase of air cavity length. The packaging of the sensing fiber increases its robustness while increasing its sensitivity from 151.30 nm/m−1 to 251.54 nm/m−1. Meanwhile, the structure is insensitive to axial stress and refractive index (RI). This sensor has potential applications in engineering health detection and small-scale structural deformation detection.

中文翻译：

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基于腔长解调的法布里-珀罗矢量曲率传感器

摘要 我们展示了一种高灵敏度的法布里-珀罗曲率传感器。其传感光纤的主要成分是中空石英管和单模光纤（SMF）。当传感器弯曲时，FPI 的长度随曲率变化。因此，我们可以通过腔长解调来实现矢量曲率测量。凸面和凹面弯曲灵敏度分别为 151.30 nm/m-1 和 -333.89 nm/m-1。此外，曲率灵敏度随着气腔长度的增加而优化。传感光纤的封装增加了其稳健性，同时将其灵敏度从 151.30 nm/m-1 提高到 251.54 nm/m-1。同时，该结构对轴向应力和折射率 (RI) 不敏感。该传感器在工程健康检测和小尺度结构变形检测等方面具有潜在的应用价值。