提出一种新颖的温度和应变双参数同时测量的光纤传感器。该传感器由空芯光纤和光纤布拉格光栅级联而成。空芯光纤通过反谐振机理将光限制在空气纤芯内传输,满足谐振条件的光泄露出空气芯,在传输光谱上表现为周期性损耗峰。由于空芯光纤和光纤布拉格光栅的物理机理不同,对外界温度、应变的响应存在差异,利用耦合矩阵则可以精确地实现温度和应变双参数的同时测量。实验结果表明,在1550 nm波长附近,空芯光纤和光纤布拉格光栅对应的温度灵敏度分别为24.55 pm/℃和12.76 pm/℃,应变灵敏度分别为-0.70 pm/με和1.02 pm/με,该级联结构的传感器制作简单且具有较高的测量精度。

A novel temperature and strain dual-parameter fiber sensor is proposed, which is constructed via the cascading between a hollow core fiber and a fiber Bragg grating. The hollow core fiber confines the light to transmit inside the air core based on the anti-resonance mechanism and the light satisfying the resonance condition leaks out of the air core, which is indicated as a periodic loss peak in the transmission spectrum. Because the physical mechanisms for hollow core fiber and fiber Bragg grating as well as their spectral responses to external temperature and strain are different, the simultaneous measurement of temperature and strain can be realized based on the coupling matrix. The experimental results show that the temperature sensitivities of hollow core fiber and fiber Bragg grating are 24.55 pm /℃ and 12.76 pm /℃ near 1550 nm wavelength, respectively. In contrast, the strain sensitivities are -0.70 pm/με and 1.02 pm/με, respectively. The proposed dual-parameter sensor is simple in fabrication and has a high measurement accuracy.