基于倏逝场和微结构光纤光栅的高灵敏度VOCs气体传感器研究

项目名称： 基于倏逝场和微结构光纤光栅的高灵敏度VOCs气体传感器研究

项目编号： No.61308055

项目类型： 青年科学基金项目

立项/批准年度： 2014

项目学科： 无线电电子学、电信技术

项目作者： 于永芹

作者单位： 深圳大学

项目金额： 26万元

中文摘要： 本项目以挥发性有机物(VOCs)的在线实时连续检测和痕量分析的应用需求为基本背景，以建立一种高灵敏度VOCs气体检测方法为目标，对基于微结构光纤长周期光栅(LPFG)和倏逝场的高灵敏度VOCs传感器中的科学问题进行较为深入的理论和实验研究。拟采用全反射型微结构光纤作为VOCs传感器的工作光纤，以光纤包层中分布的大量空气孔作为敏感区域，以飞秒激光制作LPFG作为激发倏逝场的有效手段，研究传感器的相关理论、器件结构和测量方法中的关键问题。研究不同VOCs气体的传感器特性，以及光纤结构参数和长度、LPFG的结构参数等对传感器的影响。结合微结构光纤和LPFG两者的优点，利用光纤空气孔中的倏逝场能量分布较强，与VOCs气体分子相互作用距离长的特点，研究VOCs与倏逝场的相互作用机制，实现VOCs气体的高灵敏度检测和痕量分析,无需镀任何额外的化学敏感膜，开辟一种新的VOCs测量方法和传感器结构。

中文关键词： 飞秒激光；光纤光栅；倏逝场；微结构光纤；挥发性有机物

英文摘要： To fitting the requirements of in-line and real-time detection of VOCs, a kind of VOCs sensor based on LPFG in index-guided microstructured optical fiber (MOF) and the evanescent field will be studied in this project. The index-guided MOF is used as working fibers, the air holes in cladding is used as sensitive element, Femtosecond pulse laser is applied to fabricate LPFG into MOF. The sensor key questions in theory and experiment will be studied in details. The influence of MOF structure parameters and length on the propagation characteristics,the VOCs species also will be researched.The evanescent field in the cladding will be enhanced due to a LPFG couples light resonantly from the fundamental core mode to a co-propagating higher order cladding mode. VOCs will be direct measured using LPFG without extra sensitive chemical nano-film through the evanescent field interacts with molecules of VOCs. It will open up a new way to detect VOCs in the environment. At present, the VOCs fiber sensors are usually based on LPFG coated with a polymer thin film. The field of cladding mode interacts with VOCs through the film, but the energy distributes outside the cladding is very weak and the sensitivity is limited. Meanwhile the polymer film is a key element to absorb the gas molecules. The resonant spectrum of LPFG is str

英文关键词： Femtosecond Laser；Fiber grating；Evanescent field；Microstructured optical fiber；Volatile organic compounds(VOCs) sensor