空气中飞秒激光等离子体荧光辐射光谱研究  

The fluorescence feature of plasma induced by femtosecond laser pulses in air

作　　者：郭凯敏[1,2] 高勋[1] 郝作强[1] 鲁毅[2] 孙长凯[1] 林景全[1] 

机构地区：[1]长春理工大学理学院,长春130022 [2]包头师范学院物理科学与技术学院,包头014030

出　　处：《物理学报》2012年第7期345-349,共5页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:11074027;60978014;61178022);吉林省科技厅基金(批准号:20100521;20100168;20111812);吉林省教育厅基金(批准号:[2009]40);长春市科技局国际合作项目(批准号:09GH01);光电信息控制和安全技术重点实验室基金(批准号:9140c150302110c1501)资助的课题~~

摘　　要：系统地研究了不同聚焦条件下飞秒激光空气等离子体的荧光辐射特性以及空间演化情况.在紧聚焦情况下,由于焦点附近比较高的激光强度以及比较高的电子密度,辐射光谱表现为连续谱和线状原子光谱的叠加.在弱聚焦情况下,辐射光谱主要由很多分子线谱组成,而没有观测到连续谱的产生.还研究了光谱谱线强度随激光传输距离的演化情况,结果显示,光谱谱线的强度变化在一定程度上间接反映了等离子体细丝的演化情况.Effects of focusing conditions on femtosecond laser induced plasma fluorescence in air are investigated by using different focal length lenses.Under the tightly focusing condition,the fluorescence spectra are composed mainly of continuous spectrum and line spectra from N and O atoms,which is due to the higher laser intensity and corresponding higher electron density than those in the case of weakly focused laser beam.In the latter case,only line spectra from air molecules are observed.Besides,the intensity of line spectrum as a function of propagation distance is measured,which reveals the evolution of the plasma filaments.

关 键 词：飞秒激光 等离子体细丝 荧光光谱 光学击穿 

分 类 号：O437[机械工程—光学工程]