基于表面等离子体共振的光子晶体光纤折射率传感器的设计与分析

Design and Analysis of Photonic Crystal Fiber Refractive Index Sensor Based on Surface Plasmon Resonance

摘要:

为了实现光子晶体光纤在近红外波段下的高灵敏度传感,设计了一种基于表面等离子体共振的光子晶体光纤(SPR-PCF)折射率型传感器。光纤内部的空气孔呈六边形排列,金纳米层完全包覆光纤外璧并与圆形待测物通道接触。利用有限元矢量软件COMSOL对SPR-PCF传感器的光学特性进行数值模拟仿真,得到不同待测物折射率的共振波长并绘制出纤芯损耗光谱,通过纤芯损耗光谱来对SPR-PCF传感器的传感特性进行分析。实验结果表明,其折射率测量区间为1.31~1.38,最大光谱灵敏度为10⁴nm/RIU,最大振幅灵敏度为200RIU-1,折射率测量精度为2.94×10-5RIU。

Abstract:

A surface plasmon resonance based photonic crystal fiber (SPR-PCF) refractive index sensor with high sensitivity and wide refractive index measurement interval is proposed. Using surface plasmon resonance technology to measure the change of resonance wavelength through the fundamental mode loss spectrum to achieve the purpose of measuring different refractive indices of the substance to be tested. The main purpose is to arrange the air holes inside the fiber into a hexagonal shape, and cover the gold layer on the outer side of the fiber, and contact the circular material channel to be tested. It not only helps to accelerate the surface plasma reaction, but also has a simple structure and is easy to measure. The wavelength range of its operation can be adjusted. The simulation results of COMSOL show that the refractive index measurement interval is 1.31~1.38, and the maximum spectral sensitivity of 10000nm/RIU can be obtained. The resolution is 200RIU-1, and the refractive index accuracy is 2.94×10-5RIU.