一种开放性悬芯光纤SPR传感器结构设计与性能优化

Structure Design and Performance Optimization of SPR Sensor with an Opened Suspended Core Fiber

为了同时兼顾实时流体传感与高灵敏度检测需求,结合开放式悬芯光纤与表面等离激元共振技术,设计了一种开放式三孔悬芯光纤表面等离激元共振(SPR)传感器结构.其特点是悬芯光纤中的一个大气孔对外开放,并在此气孔内侧沿着纤芯轴向设置大小、间距相同的金圆柱结构.金圆柱的存在可以激发SPR效应,通过选择合适的圆柱间距可以有效增强SPR效应与传感器灵敏度.分析了金圆柱直径、间隔和被测流体的折射率变化对传感器的传输损耗谱、场增强效应和灵敏度的影响.分析结果表明,所提出的传感器参数经优化设计后,其SPR传感灵敏度可以高达2.5×10^(-4) nm/RIU.本文研究内容对相关实时光纤SPR传感器设计具有参考价值.

Considered the requirement of fluid sensing in real time and high sensitive detection,combined the opened suspended core fiber with the technology of surface plasmon resonance,an opened three-hole suspended core fiber surface plasmon resonance sensor structure was proposed.The utility model is characterized in that an atmospheric hole in the hanging core fiber is opened to the outside,and a gold cylinder structure with the same size and the same interval is arranged along the axial direction of the core inside the air hole.The existence of gold cylinders can stimulate the SPR effect.By choosing an appropriate cylinder spacing,the SPR effect and sensor sensitivity can be effectively enhanced.It is analyzed that the effects of the change of the gold cylinder diameter,spacing,and refractive index of the measured fluid on the transmission loss spectrum,field enhancement effect,and sensitivity of the sensor.The simulation results show that the SPR sensor sensitivity can be as high as 2.5×10^（-4） nm/RIU after the proposed sensor parameters are optimized and designed.The research content has reference value for the related real-time fiber SPR sensor design.