飞秒激光诱导多丝产生与调控研究进展  

Research Progress of Femtosecond Laser-Induced Multifilament Generation and Regulation

作　　者：程俊皓 胡理想 王铁军[2] 罗剑[1] 张芳沛 余同普 Cheng Junhao;Hu Lixiang;Wang Tiejun;Luo Jian;Zhang Fangpei;Yu Tongpu(College of Sciences,National University of Defense Technology,Changsha 410073,Hunan,China;State Key Laboratory of High Field Laser Physics,Shanghai Institute of Optics and Fine Mechanics and CAS Center for Excellence in UltraIntense Laser Science,Chinese Academy of Sciences,Shanghai 201800,China;Information Science Academy of China Electronics Technology Group Corporation,Beijing 100086,China)

机构地区：[1]中国人民解放军国防科技大学理学院,湖南长沙410073 [2]中国科学院上海光学精密机械研究所强场激光物理国家重点实验室及超强激光科学卓越中心,上海201800 [3]中国电子科技集团公司信息科学研究院,北京100086

出　　处：《中国激光》2023年第14期1-13,共13页Chinese Journal of Lasers

基　　金：国家自然科学基金(11875319,U2130123,12105362);湖南省科技创新计划(2020RC4020);湖南省自科基金(2021JJ40653);中国科学院国际合作重点项目(181231KYSB20200033);上海市科技计划(21511105000)。

摘　　要：强飞秒激光在大气中的成丝过程伴随着自聚焦、群速度色散和等离子散焦等非线性光学现象,对于研究激光雷达、新型光源、人工降雨、大气污染物探测、激光远程探测和激光遥感等具有重要意义。飞秒激光在大气中传输时,通常会由于大气湍流导致的空气折射率扰动以及飞秒激光初始能量分布不均匀而产生随机多丝现象,从而影响了光丝的能量分布,缩短了光丝的传播距离并降低了光斑质量,限制了光丝的实际应用。本文介绍了近20年来国内外有关多丝调控研究的进展,分析了调节入射光束的椭圆率、改变激光场强梯度、调制激光相位、引入像散等多丝调控手段,旨在为研究飞秒激光多丝调控提供参考。这些调控手段都能在一定程度上消除多丝产生的随机性,但仍然存在多丝分布控制精度不高、激光能量损耗偏大、激光传输距离不够远等问题。因此,对多丝的调控还有待更加深入的研究。Significance The filamentation process of ultra-intense femtosecond lasers in the atmosphere is accompanied by significant nonlinear optical effects such as self-focusing,self-steepening,and plasma defocusing.This is essential for studying lidar,new light sources,artificial rainfall,air pollution detection,and laser remote sensing.When the femtosecond laser pulse is propagated into the atmosphere,a random multifilament phenomenon occurs owing to air refractive index perturbation caused by atmospheric turbulence and the initial inhomogeneous energy distribution of the femtosecond laser.This affects the energy distribution of the filament,shortens the propagation distance of the filament,and reduces the spot quality of the beam,therefore limits the practical application of the filament.This review summarizes local and international research progress on multifilaments in the past two decades.A series of multifilament control methods are reviewed,including the introduction of the elliptical rate of the incident beam,variation of the laser field gradient,modulation of the laser phase,and introduction of image dispersion to establish a reference for the study of multifilament regulation in femtosecond lasers.Progress With continuous advancements in laser technology,the peak intensity of femtosecond laser pulse obtained in laboratory tests has far exceeded the relativistic threshold(1018 W/cm^(2))and even reaches 1023 W/cm^(2),which significantly reduces the difficulty of femtosecond laser atmospheric filamentation.This serves as a foundation for experimental research and the practical application of the filament.Researchers have found that the multifilament phenomenon is mainly caused by the perturbation of the refractive index of air and the initial uneven energy distribution of the femtosecond laser.Further studies have also shown that during the formation of femtosecond laser filaments,only a small portion of the laser energy is concentrated in the filament,and most of the laser energy is stored around the filaments

关 键 词：非线性光学 飞秒激光成丝 自聚焦 多丝操控 多丝抑制 

分 类 号：O436[机械工程—光学工程]