基于侧漏型光子晶体光纤高灵敏度宽线性范围弯曲传感器的研究

基于所研制的侧漏型光子晶体光纤, 提出并研制出一种Sagnac干涉仪型高灵敏度宽线性测量范围的弯曲传感器. 实验研究结果表明, 当侧漏型光子晶体光纤中的线性缺陷与弯曲方向一致时, 采用群双折射和波谷波长偏移量测量弯曲曲率均可获得高的弯曲灵敏度, 但线性测量范围小, 且不能进行小弯曲曲率的测量. 当线性缺陷与弯曲方向垂直时, 以波谷波长偏移量进行弯曲曲率检测, 可获得10.798 nm/m^-1高灵敏度的同时且可实现0–5.03 m^-1的宽线性测量范围, 结合测量矩阵的引入可实现温度和弯曲曲率的同时测量, 进而剔除环境温度变化对弯曲曲率检测的干扰, 实现了高灵敏度宽线性范围的弯曲传感; 而以群双折射进行弯曲曲率检测, 虽然检测灵敏度较低, 但可实现对环境温度不敏感的弯曲传感. 关键词： 弯曲传感器 侧漏型光子晶体光纤 高灵敏度 宽线性范围

Curvature sensor based on side-leakage photonic crystal fiber with high sensitivity and broad linear measurement range

Based on Sagnac interferometer by incorporating a segment of side-leakage photonic crystal fiber (SLPCF), a curvature sensor with high sensitivity and broad linear measurement range was proposed and demonstrated experimentally. Experimental results show that high sensitivity to curvature can be achieved by measuring group modal birefringence and wavelength shift of transmission dip when the linear side-leakage defect is in the same direction as the bending, but the linear measuring range is not large enough to cover the small curvature. When the linear side-leakage defect is in the vertical direction to the bending, the sensitivity can be as high as 10.798 nm·m^-1 and the linear measurement range as wide as 0–5.03 m^-1 by measuring wavelength shift of transmission. Combined with the introduction of the measurement matrix, the measurement of temperature and curvature can be realized simultaneously, which would offer a way to eliminate the perturbation of the environment temperature to the measurement values of the curvature. Under the same conditions, though the sensitivity obtained by measuring group modal birefringence is low, it can be regarded as a curvature sensor which is insensitive to temperature.
Keywords： curvature sensor side-leakage photonic crystal fiber high sensitivity broad linear measurement range