空气中飞秒激光成丝的强场分子动力学研究进展  

Advances in Strong-Field Molecular Dynamics of Femtosecond Laser Filamentation in Air

作　　者：王佳辰 郭兰军[1] 张楠[1,2] 张智 林列 孙陆[1,2] Wang Jiachen;Guo Lanjun;Zhang Nan;Zhang Zhi;Lin Lie;Sun Lu(Institute of Modern Optics,Nankai University,Tianjin 300350,China;Tianjin Key Laboratory of Micro-scale Optical Information Science and Technology,Tianjin 300350,China;Tianjin Key Laboratory of Optoelectronic Sensor and Sensing Network Technology,Tianjin 300350,China)

机构地区：[1]南开大学现代光学研究所,天津300350 [2]天津市微尺度光学信息技术科学重点实验室,天津300350 [3]天津市光电传感器与传感网络重点实验室,天津300350

出　　处：《中国激光》2023年第7期19-40,共22页Chinese Journal of Lasers

基　　金：国家重点研发计划(2018YFB0504400);国家自然科学基金(12204251)。

摘　　要：高强度的飞秒激光在非线性介质成丝过程中会产生一系列非线性效应,如强场电离、转动拉曼、高次谐波、激射等,这些非线性效应与强场下分子的复杂运动有关。研究强场作用下的分子动力学问题将有助于更好地理解飞秒激光成丝过程中非线性效应背后的物理机制。综述了近年来飞秒激光在空气中成丝时主要分子动力学特性的研究进展,包括分子准直、分子电离、电子-离子复合以及分子能级的粒子数布居。最后对强场与分子相互作用研究所面临的机遇以及挑战进行了展望。Significance When a femtosecond laser is sufficiently strong to undergo filamentation in air,perturbation theory cannot be used to analyze the interaction because the laser intensity inside the filament is comparable to the Coulomb field intensity inside the molecule.The interaction between the strong laser field and molecule then produces a series of nonlinear phenomena,such as molecular alignment,ionization,high-order harmonics,terahertz radiation,and fluorescence radiation.These nonlinear phenomena are closely related to particle motion under strong fields.For example,by collecting the resulting high-order harmonics,ionized electrons,and dissociated ion signals,the internal structure of the material or dynamic process can be experimentally detected.In addition,these nonlinear phenomena have broad application prospects;for instance,filament-induced fluorescence can be used for atmospheric remote sensing,and high-order harmonics generated by laser-molecule interactions can be used to obtain high-intensity purple rays and attosecond lasers.Therefore,an in-depth study of molecular dynamics under a strong field can facilitate the elucidation of the nonlinear mechanism in the filamentation process as well as provide a theoretical basis for innovation and application.Progress This study presents a review of the main research progress concerning strong field molecular dynamics of femtosecond laser filamentation in air,including molecular alignment,molecular strong field ionization,electron-ion recombination,and population of molecular energy levels.As regards molecular alignment,researchers have conducted extensive research on its basic mechanism and have successfully used many methods to improve the alignment of molecules in experiments.Therefore,increasing research focus has been placed on more complex molecular alignment problems,such as three-dimensional alignment.In the field of molecular strong field ionization,there are many methods and models for calculating single-electron ionization,and the theoretical and e

关 键 词：非线性光学 飞秒激光成丝 强激光场 分子准直 强场电离 光丝诱导荧光 

分 类 号：O436[机械工程—光学工程]