研究了不同钯银合金原子比例复合膜对微结构光纤光栅氢气传感特性的影响.使用飞秒激光在布拉格光栅光纤包层加工螺旋微结构, 将磁控溅射方法制备的不同钯银原子比例的合金膜镀在螺旋微结构表面, 研制优化钯银合金比例的新型微结构布拉格光栅光纤氢气传感器.采用扫描电子显微镜和能谱仪对Pd-Ag薄膜进行表征和分析, 对三种不同钯银原子含量(Pd∶Ag=2∶1, 4∶1, 6∶1)的微结构布拉格光栅光纤探头进行氢气传感测试.在室温条件下, 钯银原子比例为4∶1的微结构探头具有最佳的氢气传感性能, 钯银原子比例为2∶1的微结构探头响应速度最快, 但是灵敏度最低.在4%氢气浓度下, 螺旋微结构传感器的漂移量达到107 pm, 对比同类型布拉格光栅光纤氢气传感器, 具有更高的灵敏度和更快响应速度.

The effect of Pd-Ag alloy atomic ratio composite films on the hydrogen sensing properties of microstructured Fiber Bragg Grating (FBG) was studied. The spiral microstructures were fabricated on fiber cladding using femtosecond laser. The Pd-Ag alloy films with different atomic ratio prepared by magnetron sputtering were coated on the surface of spiral microstructured FBG. A novel microstructured FBG hydrogen sensor with optimized Pd-Ag alloy ratio was developed. The Pd-Ag thin films were characterized and analyzed by scanning electron microscope and energy dispersive spectroscopy. The hydrogen sensing of three kinds of FBG probes with different Pd: Ag atomic content (Pd∶Ag=2∶1, 4∶1, 6∶1) was tested. At room temperature, the probe with Pd4-Ag1 film has the best hydrogen sensing performance. The microstructured probe with Pd-Ag atomic ratio of 2∶1 has the fastest response speed but the lowest sensitivity. The wavelength shift of the spiral micro-structured sensor towards 4%H2 is 107 pm. Compared with the same type of FBG hydrogen sensor, it has higher sensitivity and faster response time.