为了能高精度测量小曲率, 采用单模-鼓包-保偏光子晶体光纤-多模-单模光纤组成的结构, 其中多模光纤和单模光纤之间错位熔接。通过理论分析和实验验证得到在0.04582m-1~0.054776m-1及0.054776m-1~0.06929m-1曲率范围内, 谐振波长漂移与曲率变化之间分别存在着线性关系。结果表明, 该曲率传感器灵敏度值分别为93.95nm/m-1和30.89nm/m-1, 可以应用于健康监测等需要测量小曲率的场合。

For high accuracy of curvature measurement, a curvature sensor with polarization-maintaining photonic crystal fiber (PM-PCF) was proposed based on Mach-Zehnder interferometer structure. The fiber structure of the sensor head was formed by single-mode, up-taper, PM-PCF, multimode and single-mode fibers. Dislocation fusion was done between multimode and single mode fibers. After theoretical analysis and experiment verification, the linear relationship between resonance wavelength shift and curvature change in the curvature range of 0.04582m-1~0.054776m-1 and 0.054776m-1~0.06929m-1 was proved. The results show that the curvature sensor can be implied in health monitoring when the sensitivities of the sensor are 93.95nm/m-1 and 30.89nm/m-1.