光纤表面等离子体共振传感器理论仿真研究

摘要

In order to examine the sensing properties of optical fiber sensors based on surface plasmon resonance, the reflective spectral properties of the sensors have been investigated based on Snell reflection formula for single layer thin film by means of MatLab software. The influence of gold film thickness, the permittivity of the external medium and incident angle on the boundary of optical fiber core and cladding on the reflective spectral properties has been systematically studied. The results of the simulation show that the resonance wavelength increases with increasing gold film thickness, and decreasing with increasing permittivity of the external medium. It is also found that the full-width half-maximum of the resonance absorbing peak increases with increasing the incident angle and the minimums of the reflectivities at resonance peaks gradually decrease, leading to the decrease of the sensitivity.%为了考查光纤表面等离子体共振传感器的传感特性,基于单层膜表面Snell反射公式,利用MatLab软件仿真研究光纤表面等离子体共振(SPR)传感器的反射光谱特性,系统考查金膜厚度、待测介质介电常数以及入射到纤芯—金膜界面的入射角对反射光谱特性的影响.仿真结果表明:光纤SPR的共振波长随金膜厚度的增大而增大,随外界介质介电常数的增大而减小；随着入射角的增大,共振吸收峰半峰宽逐渐增大,共振峰处的反射率最小值逐渐变小,传感灵敏度降低.