契形结构光纤表面等离子体共振传感器研究

提出了一种契形端面结构的光纤表面等离子体共振(SPR)传感器激励模型. 采用时域有限差分法对契形SPR波导的共振模型进行数值模拟, 通过在光纤出射端抛磨契形角度并进行敏感膜修饰, 制出具有契形端面结构的类Kretschmann微棱镜式光纤SPR传感器, 实现激发SPR的光波调制.结果表明, 在1.3330–1.4215折射率范围内, 制备的契形光纤SPR传感器相对于常规光纤SPR传感器, 其平均灵敏度提高了近1–6倍, 1倍和6倍分别出现在小角度结构(15° 契形) 传感器和大角度结构(60°契形) 传感器, 且仍保持 10^-5 等级的分辨率. 该类型结构的传感器具有契形端面激励模式, 设计灵活性高、制备工艺简单、可微量检测样本等优点, 能够很好地适应于不同环境和测量条件的实际生化检测、环境监测需求. 关键词： 光纤传感器 表面等离子体共振 契形端面结构 折射率灵敏度

Development of fiber-optic surface plasmon resonance sensor based on tapered structure probe

A fiber-optic surface plasmon resonance sensor (SPR) based on tapered structure probe is studied. The incentive mode of tapered probe calculated by finite-difference time-domain method serves as design references, and the tapered structure of sensor probe fabricated by polishing and grinding at the end of a fiber is similar to Kretschmann prism SPR model, which can realize the modulation of SPR wave. The results show that in the refractive index detection range from 1.3330 to 1.4215, tapered structure FO-SPR sensor has a sensitivity of 1-6 times higher than common FO-SPR sensor and it still keeps a limiting resolution level of 10^-5 RIU. The designed tapered structure SPR sensor, which has the advantages of tapered incentive mode, design flexibility, user practical applicability, simple preparation process, a relatively small sample need, and high stability, will fulfill different environment and measuring conditions of biochemical testing and environment monitoring.
Keywords： fiber-optic sensor surface plasmon resonance tapered structural model sensitivity of refractive index