A fiber optic temperature sensor consisting of two cascaded high birefringence fiber loop mirrors (Hi-Bi FLMs) was proposed and experimentally demonstrated to enhance the temperature sensitivity and resolution by Vernier effect. The FSRs for the two Hi-Bi FLMs are designed to be slightly different to generate the Vernier effect. The working principle for the proposed sensor is analogous to Vernier-scale, one Hi-Bi FLM acts as a reference, while the other is for temperature sensing. The temperature sensitivity and resolution for the cascaded configuration are much higher than those for single Hi-Bi FLM due to the Vernier effect. A Gauss fitting algorithm is introduced to fit the Vernier spectral envelope to accurately trace the wavelength shift of the envelope peak. Experimental result shows that the temperature sensitivity and resolution can be improved from − 2.24 nm/°C and ± 0.0223 °C (single Hi-Bi FLM) to − 23.68 nm/°C and ± 0.0021 °C (cascaded configuration), respectively. The enhancement factors for temperature sensitivity and resolution are both 10.6, which are in good agreement with the theoretical prediction (10.7). The proposed sensor with high sensitivity, accuracy, easy fabrication and low cost is highly desirable for some applications that needs precise temperature control, such as micro-nano satellites, lasers, some chemical reaction process and enzyme reaction process.

提出了由两个级联的高双折射光纤环形镜（Hi-Bi FLM）组成的光纤温度传感器，并通过实验证明了通过Vernier效应提高温度灵敏度和分辨率。两个Hi-Bi FLM的FSR设计为略微不同，以产生游标效果。拟议中的传感器的工作原理类似于Vernier规模，一种Hi-Bi FLM用作参考，另一种用于温度感测。由于游标效应，级联配置的温度灵敏度和分辨率远高于单个Hi-Bi FLM。引入了高斯拟合算法来拟合Vernier光谱包络，以准确跟踪包络峰的波长偏移。实验结果表明，温度灵敏度和分辨率可以分别从− 2.24 nm /°C和±0.0223°C（单个Hi-Bi FLM）提高到− 23.68 nm /°C和±0.0021°C（级联配置）。温度灵敏度和分辨率的增强因子均为10.6，与理论预测值（10.7）吻合良好。对于一些需要精确温度控制的应用，例如微纳米卫星，激光，某些化学反应过程和酶反应过程，提出的具有高灵敏度，准确性，易于制造和低成本的传感器是非常需要的。与理论预测值（10.7）吻合良好。对于一些需要精确温度控制的应用，例如微纳米卫星，激光，某些化学反应过程和酶反应过程，提出的具有高灵敏度，准确性，易于制造和低成本的传感器是非常需要的。与理论预测值（10.7）吻合良好。对于一些需要精确温度控制的应用，例如微纳米卫星，激光，某些化学反应过程和酶反应过程，提出的具有高灵敏度，准确性，易于制造和低成本的传感器是非常需要的。