为增强基于Ag膜光纤表面等离子体共振(SPR)传感器的抗氧化能力,可将Au膜镀于Ag膜表面。利用TFCalc软件对不同厚度Ag膜和ALl.Ag复合膜的光纤SPR传感特性进行理论仿真研究。仿真结果表明:光纤SPR吸收峰显著依赖于Ag膜厚度,当Ag膜厚度由40nm逐渐增加到80nm时,共振吸收峰的半峰全宽逐渐减小,且共振波长随Ag膜厚度的增大而减小,共振波长变化范围较小,仅为7nm左右;Au膜的引入对共振吸收峰反射率影响不大,不同厚度Au_Ag复合膜的SPR共振波长随Au膜厚度的增大而增大。
In order to improve the anti-oxidation ability of optical fiber surface plasmon resonance sensor based on silver thin films, it is possible to deposit gold thin film onto silver thin film. The reflective spectral properties of the sensors with different thickness of Ag and Au-Ag thin films have been investigated by means of TFCalc software. The results of the simulation show that the resonance absorbing peaks of optical fiber SPR remarkably depend on silver thickness. The full-width half-maximum of the resonance absorbing peak decreases when the film thickness of silver thin film increases from 40 nm to 80 nm. It is also found from the simulation results that the resonance wavelength decreases with increasing silver film thickness and the variation range of the absorbing wavelength is as narrow as less than 7 nm. Moreover, it is also found that the gold thin film has no significant effect on the reflectivity of the resonance absorbing peaks, and the absorbing wavelength increases with the increase of the thickness of gold thin film in the Au-Ag composite films.