融锥多芯光纤弯曲传感器

Bending Sensor Based on Tapered Multicore Fiber

利用光纤熔融拉锥技术,对一种中心对称、具有较大芯间距的多芯光纤进行了优化。融锥后的光纤具有倏逝场强、传感灵敏度高的特点,但由于其柔韧性差难于用作弯曲传感测量。本文设计了一种柔性传感器,使优化后的融锥光纤可用于弯曲传感测量。利用超模耦合理论对优化后多芯光纤传感器的透射谱进行了分析,并对其弯曲传感特性进行了实验研究。实验结果表明,该柔性融锥光纤传感器的干涉条纹与弯曲曲率有很好的线性关系。优化后的融锥光纤弯曲传感器的灵敏度为2.90 nm/m^(−1)。

A fiber tapering technique is used to optimize a central symmetry multicore fiber that has a large core spacing.The tapered fiber has the characteristics of a strong evanescent field and high sensing sensitivity;however,it is difficult to use as a bending sensor because of its poor flexibility.This paper proposes a flexible structure design so that the optimized tapered fiber can be used as a bending sensor.The transmission spectrum of the optimized multicore optical fiber sensor is analyzed using supermode coupling theory.In addition,the bending sensing characteristics of the sensor are experimentally studied.The experimental results indicate that there is a good linear relationship between the interference fringes and bending curvature.The sensitivity of the optimized tapered fiber sensor is 2.90 nm/m^(−1).