High-Sensitivity Gas Detection with Air-Lasing-Assisted Coherent Raman Spectroscopy  

作　　者：Zhihao Zhang Fangbo Zhang Bo Xu Hongqiang Xie Botao Fu Xu Lu Ning Zhang Shupeng Yu Jinping Yao Ya Cheng Zhizhan Xu 

机构地区：[1]State Key Laboratory of High Field Laser Physics,Shanghai Institute of Optics and Fine Mechanics,Chinese Academy of Sciences,Shanghai 201800,China [2]University of Chinese Academy of Sciences,Beijing 100049,China [3]School of Physical Science and Technology,ShanghaiTech University,Shanghai 200031,China [4]School of Science,East China University of Technology,Nanchang 330013,China

出　　处：《Ultrafast Science》2022年第2期1-8,共8页超快科学（英文）

基　　金：supported by the National Natural Science Foundation of China(11822410,12034013,12074063);Key Research Program of Frontier Sciences of Chinese Academy of Sciences(QYZDJ-SSW-SLH010);Program of Shanghai Academic Research Leader(20XD1424200);Shanghai Municipal Science and Technology Major Project(2019SHZDZX01);Youth Innovation Promotion Association of CAS(2018284).

摘　　要：Remote or standoff detection of greenhouse gases,air pollutants,and biological agents with innovative ultrafast laser technology attracts growing interests in recent years.Hybrid femtosecond/picosecond coherent Raman spectroscopy is considered as one of the most versatile techniques due to its great advantages in terms of detection sensitivity and chemical specificity.However,the simultaneous requirement for the femtosecond pump and the picosecond probe increases the complexity of optical system.Herein,we demonstrate that air lasing naturally created inside a filament can serve as an ideal light source to probe Raman coherence excited by the femtosecond pump,producing coherent Raman signal with molecular vibrational signatures.The combination of pulse self-compression effect and air lasing action during filamentation improves Raman excitation efficiency and greatly simplifies the experimental setup.The air-lasing-assisted Raman spectroscopy was applied to quantitatively detect greenhouse gases mixed in air,and it was found that the minimum detectable concentrations of CO_(2) and SF_(6) can reach 0.1%and 0.03%,respectively.The ingenious designs,especially the optimization of pump-seed delay and the choice of perpendicular polarization,ensure a high detection sensitivity and signal stability.Moreover,it is demonstrated that this method can be used for simultaneously measuring CO_(2) and SF_(6) gases and distinguishing ^(12)CO_(2) and ^(13)CO_(2).The developed scheme provides a new route for high-sensitivity standoff detection and combustion diagnosis.

关 键 词：PUMP polarization LASING 

分 类 号：TN2[电子电信—物理电子学]