提出一种基于铜沉积石墨烯涂层光子晶体光纤马赫-曾德干涉的硫化氢气敏传感器.将45 mm光子晶体光纤两端与单模光纤进行拉锥熔接，使得光子晶体光纤的空气孔熔接时形成塌陷层，更好地激发包层模式，形成基于马赫-曾德结构的干涉仪.采用单层石墨烯粉体，加入异丙醇分散液，反复浸涂至光子晶体光纤包层表面形成石墨烯涂层，并沉积铜纳米颗粒，使传感器对硫化氢气体具有高的响应度.实验结果表明，在硫化氢气体浓度为0~60 ppm范围内，随着被测气体浓度不断增大，其输出光谱呈现明显蓝移，传感器灵敏度为0.042 03 nm/ppm，且线性度良好.该传感器成本低、灵敏度高、结构简单，适用于低浓度硫化氢气体的在线监测.

A hydrogen sulfide gas sensor based on Cu-deposited graphene-coated tapered Photonic Crystal Fiber (PCF) Mach-Zehnder Interferometer (MZI) was proposed and fabricated. The PCF-MZI was formed by fusion splicing a PCF with length of 45 mm which was sandwiched between two Single-Mode Fibers (SMF), and the air holes of PCF in the splicing regions were fully collapsed, and then it could motivate the cladding modes better. Using isopropanol as dispersion agent, the monolayer powders of graphene were added in the solution and fully dispersed, and then the PCF was dip-coated and sintered repeatedly. Cu-deposited graphene-coated PCF was used to make the sensor produce high sensitivity. The results show that with the increasing concentration of hydrogen sulfide, the output wavelengths appear blue shift, and a high hydrogen sulfide gas sensitivity of 0.042 03 nm/ppm and good linear relationship are obtained within a measurement range from 0 to 60 ppm for hydrogen sulfide gas. The system has the advantages of low cost, high sensitivity and simple structure, especially suitable for low concentration and on-line monitoring of hydrogen sulfide gas.