外文题目: Population Redistribution Among Multiple Electronic States of Molecular Nitrogen Ions in Strong Laser Fields
作者: Yao, Jinping; Jiang, Shicheng; Chu, Wei; Zeng, Bin; Wu, Chengyin; Lu, Ruifeng; Li, Ziting; Xie, Hongqiang; Li, Guihua; Yu, Chao; Wang, Zhanshan; Jiang, Hongbing; Gong, Qihuang; Cheng, Ya
刊名: Phys. Rev. Lett.
年: 2016 卷: 116 期: 14 文章编号：143007
英文关键词:

MULTIELECTRON DYNAMICS; IONIZATION; DIFFRACTION; GENERATION; ORBITALS; WAVE; AIR
英文摘要:
We carry out a combined theoretical and experimental investigation on the population distributions in the ground and excited states of tunnel-ionized nitrogen molecules at various driver wavelengths in the near- and midinfrared range. Our results reveal that efficient couplings (i.e., population exchanges) between the ground N-2(+)(X-2 Sigma(+)(g)) state and the excited N-2(+)(A(2)Pi(u)) and N-2(+)(B-2 Sigma(+)(u)) states occur in strong laser fields. The couplings result in a population inversion between the N-2(+)(X-2 Sigma(+)(g)) and N-2(+)(B-2 Sigma(+)(u)) states at wavelengths near 800 nm, which is verified by our experimental observation of the amplification of a seed at similar to 391 nm. The result provides insight into the mechanism of free-space nitrogen ion lasers generated in remote air with strong femtosecond laser pulses.


文献类型: 期刊论文
正文语种: English
收录类别: SCIEI
DOI: 10.1103/PhysRevLett.116.143007


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