反射式光纤表面等离子体波共振传感器特性研究

研究了一种基于表面等离子体波共振(SPR)光谱分析的折射率检测新方法。研究发现,表面等离子体波共振效应光谱特征的折射率灵敏度会随着液体性质变化而发生改变。根据折射率测量范围不同,分别选择共振波长和共振强度作为检测参量,实现理论折射率分辨力达到10~(-5)数量级以上。在理论分析和实验基础上,设计出一种基于共振光强检测的终端反射式光纤表面等离子体波共振效应传感系统,采用将传感信号和基准光信号的比值作为液体折射率变化的度量值。在1．3325～1．3991的折射率测量范围内,度量值与折射率之间呈现单调递减关系,线性相关系数为0．9983。通过定义耦合系数,还可实现对表面等离子体波共振效应效应强弱和变化趋势的评估。

Reflective Optical Fiber Surface Plasma Wave Resonance Sensor

A novel approach for measurement of refractive index based on analysis of surface plasma resonance (SPR) spectrum is proposed. It is found that the variety of liquid characteristics will lead to the change of refractive index sensitivity of SPR spectrum. According to the different range of refractive index, resonance wavelength and resonance intensity can serve as measuring parameters, respectively. The refractive index resolution can reach 10-5 theoretically by using this method. Based on theoretical analysis and experiment, a reflective optical fiber SPR sensor system based on resonance light intensity interrogation is designed and demonstrated, and the ratio of sensing signal and reference signal is used as the measurement value of refractive index. In the refractive index range of 1.3325～1.3991, the measurement value decreases with the increase of refractive index, with a linearity of 0.9983. In addition, the coupling coefficient, which can be used to estimate intensity and change trend of SPR effect, is researched.