应用于C_(2)H_(2)吸收光谱检测的单孔单芯内悬挂光纤  

Single-hole single-core internally suspended fiber for C_(2)H_(2) absorption spectroscopy detection

作　　者：陈锦玲 刘华北 管祖光 凌强 邵杰[2] 张卓鹏 陈达如 CHEN Jinling;LIU Huabei;GUAN Zuguang;LING Qiang;SHAO Jie;ZHANG Zhuopeng;CHEN Daru(Hangzhou Institute of Advanced Studies,Zhejiang Normal University,Hangzhou 311200,China;Institute of Information Optics,Zhejiang Normal University,Jinhua 321004,China)

机构地区：[1]浙江师范大学杭州高等研究院,浙江杭州311200 [2]浙江师范大学信息光学研究所,浙江金华321004

出　　处：《浙江师范大学学报（自然科学版）》2021年第3期259-263,共5页Journal of Zhejiang Normal University:Natural Sciences

基　　金：浙江省自然科学基金资助项目(LY19F050014,LY19F050015);杭州领先创新创业团队资助项目(STD013)。

摘　　要：为了提高基于激光吸收光谱技术的C_(2)H_(2)气体检测灵敏度,替代多通池在吸收光谱检测中的功能,设计了一种应用于C_(2)H_(2)吸收光谱检测的特殊微结构光纤,即单孔单芯内悬挂光纤.以C_(2)H_(2)吸收谱线{1.5316μm}的激光作为工作波长,基于有限元方法计算了光纤的模场分布,分析了光纤纤芯半径r、纤芯折射率n-1及包层厚度D对基模中空气内层能量占比的影响,并获得了优化的光纤参数(空气内层半径R=25μm,纤芯半径r=0.49μm,纤芯折射率n_(1)=1.72;包层厚度D=5μm,折射率为n_(2)=1.45).提出了该光纤用于C_(2)H_(2)检测的方案,理论计算该光纤在光程1 km的情况下获得10^(-13)量级的探测极限.In order to improve the sensitivity of C_(2)H_(2)gas detection based on laser absorption spectroscopy,and replace multi-pass cell in absorption spectroscopy detection,a special micro-structured optical fiber,namely a single-hole single-core internally suspended fiber,for C_(2)H_(2)absorption spectroscopy was designed.By using the C_(2)H_(2)absorption line 1.5316μm as the working wavelength,the mode field distribution of the fiber was calculated based on the finite element method.Fiber core radius r,core refractive index n-1 and cladding thickness D were analyzed for the influence of the energy ratio of the air inner layer and the fiber core for the fundamental mode.The optimized fiber parameters were obtained,which were air inner layer radius R=25μm,core radius r=0.49μm,and refractive index of the fiber core n_(1)=1.72,cladding thickness D=5μm,and cladding refractive index n_(2)=1.45.A C_(2)H_(2)detection scheme based on the single-hole single-core internally suspended fiber was proposed.The theoretically calculation showed that a detection limit of 10^(-13)level based on a 1 km fiber could be achieved.

关 键 词：有限元分析 激光光谱技术 微结构光纤 痕量气体检测 

分 类 号：O433[机械工程—光学工程]