Zhou Di, Ullah Sajid, Zhang Sa, Li Shuguang
State Key Laboratory of Metastable Materials Science & Technology and Key Laboratory for Microstructural Material Physics of Hebei Province, School of Science, Yanshan University, Qinhuangdao 066004, China.
Sensors (Basel). 2024 Dec 19;24(24):8132. doi: 10.3390/s24248132.
Methane gas leakage can lead to pollution problems, such as rising ambient temperature. In this paper, the Vernier effect of a double D-shaped photonic crystal fiber (PCF) in a Sagnac interferometer (SI) is proposed for the accurate detection of mixed methane gas content in the gas. The optical fiber structure of the effective sensing in the sensing SI loop and the effective sensing in the reference SI loop are the same. Both of them adopt the polarization-maintaining photonic crystal fiber (PM-PCF) designed in this paper. The optical fiber structure of the effective sensing in the sensing SI loop deposited with the methane gas-sensitive film is polished to obtain a double-D structure. This operation makes it easier for methane gas to contact the sensitive film and realize the sensor's repeated use. The sensing capability of the methane gas sensor was evaluated utilizing the finite element method (FEM). The numerical simulation results show that when the concentration of methane gas in the environment is 0~3.5%, the average sensitivity of two parallel Sagnac loops is 409.43 nm/%. Using Vernier effect cascade SI loops, the sensitivity of the sensor for detecting methane gas increased by four times. Without considering air and humidity, we provide a practical scheme for the development and design of high-sensitivity methane gas sensors.
甲烷气体泄漏会导致污染问题，比如环境温度升高。本文提出将双D形光子晶体光纤（PCF）在萨格纳克干涉仪（SI）中的游标效应用于精确检测气体中混合甲烷气体的含量。传感SI环中有效传感的光纤结构与参考SI环中有效传感的光纤结构相同。它们都采用本文设计的保偏光子晶体光纤（PM-PCF）。对沉积有甲烷气敏膜的传感SI环中有效传感的光纤结构进行抛光以获得双D结构。这一操作使甲烷气体更容易接触敏感膜并实现传感器的重复使用。利用有限元方法（FEM）评估了甲烷气体传感器的传感能力。数值模拟结果表明，当环境中甲烷气体浓度为0~3.5%时，两个平行萨格纳克环的平均灵敏度为409.43 nm/%。利用游标效应级联SI环，传感器检测甲烷气体的灵敏度提高了四倍。在不考虑空气和湿度的情况下，我们为高灵敏度甲烷气体传感器的开发与设计提供了一种切实可行的方案。
