研究介绍了一种基于表面等离子体共振(SPR)原理,对氢气浓度变化有较高灵敏度的基于银/钯复合膜的光纤氢气传感器。通过对建立侧边抛磨“D”型光纤的光学模型用Mode—Sloutions软件进行数值仿真,结果表明侧边抛磨光纤SPR模式的有效折射率随感应区的折射率增加而增加,随包层材料的厚度增加而减小。实验结果表明,感应区氢气体积分数为4%时,光纤输出的透射功率变化可达130nW。这种Pd/Ag复合膜光纤SPR氢敏传感器不仅改善了氢敏传感器的敏感膜的稳定性,而且灵敏度也提高了,对于制备新型、优化的化学和生物传感器件有参考意义。
A Pd/Ag metal-coated optical fiber sensor with high sensitivity to hydrogen concentrations change which is achieved by exciting surface plasmon resonance (SPR) is presented. Simulation results show that with the increase of the refractive index of sensing area, effective refractive index of the SPR mode of metal-coated side-polished "D" shape fiber increases; while with the increase of the thickness of metal coating, the effective refractive index of the SPR decreases. Experimental results show that when the hydrogen concentration is 4 % , transmission power changes as high as 130 nW. The fiber optic SPR sensor improve the stability and sensitivity of the the hydrogen sensor. This sensor would be of great interest to produce novel and enhanced devices for chemical and biological sensing.