Zhou Jianming, Zhi Yanyan, Zhang Junyi, Yao Jianping, Zhang Junkai, Zhang Jiejun
Guangdong Provincial Key Laboratory of Optical Fiber Sensing and Communication, Institute of Photonics Technology, Jinan University, Guangzhou 510632, China.
College of Physics & Optoelectronic Engineering, Jinan University, Guangzhou 510632, China.
Sensors (Basel). 2024 Dec 25;25(1):38. doi: 10.3390/s25010038.
This work presents a high-sensitivity temperature sensing system utilizing an enhanced Vernier effect implemented in cascaded fiber loop interferometers. High-sensitivity temperature sensors based on the Vernier effect have broad application prospects, but the sensitivity of traditional measurement schemes is difficult to improve further due to the limited variation in the difference between two free spectrum ranges (FSRs). Our sensing system incorporates two fiber loop interferometers and a single-mode fiber to form a Vernier spectral response, characterized by two complementary optical filter responses. As the temperature of the sensing fiber changes, one FSR decreases, and the other increases, respectively, enhancing the difference value between the two FSRs to form an enhanced Vernier effect. Experimental results demonstrate that the temperature sensitivity of a traditional Vernier effect measurement is only -298.29 kHz/°C, while our proposed enhanced Vernier effect sensing system achieves a sensitivity of 618.14 kHz/°C, which is 92 times higher than that of a two-arm optical carrier-based microwave interferometry (OCMI) sensing system and 2.07 times higher than that of a traditional Vernier effect sensing system. This approach with an enhanced Vernier effect scheme based on cascaded fiber loop interferometers can be used to design high-sensitivity sensing systems for biometrics, smart cities, and the Internet of Things.
这项工作提出了一种利用级联光纤环干涉仪中实现的增强型游标效应的高灵敏度温度传感系统。基于游标效应的高灵敏度温度传感器具有广阔的应用前景，但由于两个自由光谱范围（FSR）之间差值的变化有限，传统测量方案的灵敏度难以进一步提高。我们的传感系统包含两个光纤环干涉仪和一根单模光纤，以形成游标光谱响应，其特征在于两个互补的光学滤波器响应。随着传感光纤温度的变化，一个FSR减小，另一个FSR增大，分别增强了两个FSR之间的差值，从而形成增强型游标效应。实验结果表明，传统游标效应测量的温度灵敏度仅为-298.29 kHz/°C，而我们提出的增强型游标效应传感系统的灵敏度达到618.14 kHz/°C，比基于双臂光载波的微波干涉测量（OCMI）传感系统高92倍，比传统游标效应传感系统高2.07倍。这种基于级联光纤环干涉仪的增强型游标效应方案可用于设计用于生物识别、智慧城市和物联网的高灵敏度传感系统。
