基于经验模态分解的折射率、pH和温度三参量同时检测光纤传感器  

Optical Fiber Sensors for Simultaneous Detection of Refractive Index,pH,and Temperature Based on Empirical Mode Decomposition

作　　者：闵洋 常建华[1,2] 柯欣怡 吴新新 Min Yang;Chang Jianhua;Ke Xinyi;Wu Xinxin(School of Electronics&Information Engineering,Nanjing University of Information Science&Technology,Nanjing 210044,Jiangsu,China;Collaborative Innovation Center of Atmospheric Environment and Equipment Technology,Nanjing University of Information Science&Technology,Nanjing 210044,Jiangsu,China)

机构地区：[1]南京信息工程大学电子与信息工程学院,江苏南京210044 [2]南京信息工程大学江苏省大气环境与装备技术协同创新中心,江苏南京210044

出　　处：《光学学报》2024年第23期53-64,共12页Acta Optica Sinica

基　　金：国家自然科学基金(62175114,62375137)。

摘　　要：提出了一种基于表面等离子体共振(SPR)和马赫-曾德尔干涉(MZI)效应结合经验模态分解(EMD)同时对折射率、pH和温度进行检测的光纤传感器。该传感器由空芯光纤(HCF)与两段多模光纤(MMF)构成,利用银纳米膜和聚丙烯酸/壳聚糖(PAA/CS)高折射率pH敏感材料将HCF的侧面划分成区域Ⅰ和区域Ⅱ,分别用于测量折射率(单位为RIU)和pH。通过EMD将区域Ⅲ中由环境温度变化所产生的MZI干涉光谱分解为本征模态函数(IMF),建立温度变化与IMF之间的关系,扩大对温度变化的动态测量范围,实现温度补偿。实验结果显示,传感器在1.333~1.370折射率范围内的灵敏度达到了2381.71 nm/RIU,在4.12~10.14的pH值范围内的灵敏度为-14.62 nm/pH,在20~80℃温度范围内的温度灵敏度为85.27 pm/℃,在海洋环境监测、生物化学检测等领域具有广泛的应用前景。Objective In recent years,with the improvement of sensor accuracy and performance requirements in biomedicine,chemical sensing,and environmental monitoring,the demand for multi-parameter simultaneous monitoring is growing.For example,in marine environmental monitoring,it is necessary to detect the refractive index,pH,and temperature simultaneously.However,most current sensors have complex structures,poor mechanical strength,and small dynamic measurement ranges,making it difficult to meet the simultaneous measurement needs in complex environments.Therefore,it is essential to develop a kind of optical fiber sensor with simple structures,high performance,and large measurement ranges,which can realize multi-parameter simultaneous detection in complex environments.We propose an optical fiber sensor based on surface plasmon resonance(SPR)and Mach‒Zehnder interference(MZI)effects combined with empirical mode decomposition(EMD)to simultaneously detect the refractive index,pH,and temperature.Methods We combine the SPR and MZI effects in the multimode optical fiber-hollow core optical fiber-multimode opticalfiber (MMF-HCF-MMF) structure with EMD to achieve simultaneous detection of the refractive index, pH, andtemperature. First, the principles of the two effects are analyzed, the performance parameter formulas of SPR and MZI arederived, and simulation is adopted to verify the feasibility of the theory. Meanwhile, we analyze the principles and steps ofEMD and its effectiveness in enhancing the free spectral range (FSR) of the interference spectrum. Then, an optical fibersensor based on the MMF-HCF-MMF structure is fabricated, and the side of HCF is divided into region I and region II bysilver nanofilm and polyacrylic acid/chitosan (PAA/CS), which are employed to measure the refractive index and pHrespectively. Additionally, the MZI interference spectrum generated by the ambient temperature change in the region-Ш isdecomposed into intrinsic mode functions (IMFs) via EMD to achieve temperature measurement. Finally, a refr

关 键 词：表面等离子体共振 马赫-曾德尔干涉仪 经验模态分解 多参数传感 

分 类 号：TP212[自动化与计算机技术—检测技术与自动化装置]