提出了一种基于铜沉积二硫化钨膜包覆薄芯光纤的马赫-曾德尔干涉型气体传感器。将标准单模光纤与薄芯光纤熔接形成纤芯失配型气体传感器,借由外表面沉积铜的二硫化钨敏感膜对硫化氢气体的吸附,将气体的浓度与光谱偏移关联起来,从而达到检测低浓度硫化氢气体的目的。研究表明,该传感器对硫化氢气体的检测灵敏度为29.3 pm,且在硫化氢气体体积分数为0~6×10 ^-5的范围内显示出良好的线性关系和选择性。该传感器结构简单、灵敏度高、制备容易,特别适用于硫化氢气体的低浓度在线监测。

A gas sensor based on the Mach-Zehnder interferometer with copper-deposited tungsten disulfide coated thin-core fiber is proposed. The fiber-core mismatch-type gas sensor is formed by fusion of standard single-mode fiber and thin-core fiber. The relation between the gas concentration and the spectral shift is established by the adsorption of the copper-deposited tungsten disulfide film to the hydrogen sulfide gas. Therefore, the detection of the hydrogen sulfide gas with lower concentration can be achieved. The experimental results show that the detection sensitivity of the hydrogen sulfide gas is 29.3 pm and the sensor has a good linearity and selectivity within the gas volume fraction range of 0~6×10 -5. The sensor is especially suitable for online monitoring of hydrogen sulfide gas with low concentration for the advantages of simple structure, high sensitivity and easy to manufacture.