针对双芯光纤传感器在应用中存在的环境温度交叉敏感的问题, 文章提出并设计了一种长周期双芯光纤光栅温度-弯曲双参量传感器, 对其传感特性进行了数值分析与研究。结果显示, 在20~60 cm曲率半径范围和0~100 ℃温度范围内, 波长向长波方向漂移, 实现的最大弯曲灵敏度为0.205 nm/cm, 最大温度灵敏度为1.208 nm/℃。当波长分辨率为0.1 nm时, 长周期双芯光纤光栅可以分别实现0.2 cm的弯曲传感分辨率和0.079 ℃的温度传感分辨率。所设计的双参量传感器结构简单、灵敏度高, 可用于轨道和桥梁等建筑的形状监测, 同时可有效排除环境温度干扰。

In term of the cross-sensitivity problem of ambient temperature in the process, a double-parameter sensor based on Twin-Core Fibers (TCF) and Long Period Gratings (LPG) is proposed. The theoretical mode is established, and the stimulated analysis is performed. The simulation results show that the bending sensitivity of 0.205 nm/cm with the micro-bending range of 20~60 cm and the temperature sensitivity of 1.208 nm/℃ with the temperature range of 0~100 ℃ are achieved. Based on a spectrometer having a wavelength distinguishability of 0.1 nm, the sensor can reach a distinguishability of 0.2 cm for bending and 0.079 ℃ for temperature. This sensor has advantages of simple structure and high sensitivity, and can effectively eliminate interference of ambient temperature which is available for shape monitoring of buildings such as tracks and bridges.