相向成丝荧光增强光谱检测技术研究  

Research on Detection Technology of Fluorescence Enhanced Spectroscopy Based on Counter-Propagating Filaments

作　　者：王小月 施皓天 王子健 彭博 闫明 刘伟伟[3] Wang Xiaoyue;Shi Haotian;Wang Zijian;Peng Bo;Yan Ming;Liu Weiwei(State Key Laboratory of Precision Spectroscopy,East China Normal University,Shanghai 200062,China;College of Optical and Electronic Technology,China Jiliang University,Hangzhou 310018,Zhejiang,China;Institute of Modern Optics,Nankai University,Tianjin 300071,China)

机构地区：[1]华东师范大学精密光谱科学与技术国家重点实验室,上海200062 [2]中国计量大学光学与电子科技学院,浙江杭州310018 [3]南开大学现代光学研究所,天津300071

出　　处：《中国激光》2023年第7期77-82,共6页Chinese Journal of Lasers

基　　金：科技部重点研发计划(2018YFB0504400)。

摘　　要：探索了一种基于两束相向传播飞秒光丝诱导荧光的光谱检测方法。实验结果表明,该方法能够延长荧光衰减时间,增强物质特征谱线强度。将该方法应用于盐水溶液中金属离子(K^(+)、Na^(+)、Mg^(2+))特征峰及含量的检测,其对Na^(+)含量的检测灵敏度为4.3×10^(-6),较相同激发脉冲能量下的单丝诱导荧光检测技术提升了4倍,且具有良好的线性度。该方法有望为污染物检测提供新途径。Objective Laser-induced fluorescence spectroscopy (LIFS) is a novel spectroscopic technique with several advantages,such as multi-elemental simultaneous detection,rapid response,and real-time online monitoring;hence,it is a powerful tool for remote sensing.However,single-beam laser filamentation remains limited,including the limitation of fluorescence signal intensity and detection sensitivity owing to the influence of intensity clamping.Several methods have been proposed to address these problems.For instance,the fluorescence signal can be enhanced by the interaction between two or more filaments,which is crucial in improving the sensitivity of substance detection.Previous studies about the interactions between co-propagation filaments often adopted multiple femtosecond pulses to form plasma gratings in the medium and increase the fluorescence signal intensity.However,such methods rely on the spatial interference effect of an ultrafast light field.They have high requirements for parameters such as the excitation beam’s spatial angle and pulse delay.To circumvent the aforementioned problems,we study the interaction mechanism of collinear counter-propagating filaments and their influence on fluorescence properties.Experiment results demonstrate that although its enhancement effect on fluorescence can be comparable to that of the co-propagating filament,it is almost not affected by the laser polarization.Applying this technology to the spectroscopic detection of metal ions in compounds is expected to provide a novel approach to detecting trace contaminants by studying the linear relationship between characteristic spectral intensity and substance concentration.Methods We establish a collinear counter-propagating filaments (CPF) system,which comprises two collinear beams propagating in the opposite direction and focusing on the same focus through a lens,thereby forming two spatially overlapping counter-propagating filaments near the focus.We make precise adjustments using the electronic translation platform to bet

关 键 词：光谱学 光丝 荧光光谱 飞秒激光 

分 类 号：O436[机械工程—光学工程]