空间非均匀场调控H2+分子谐波辐射的研究

J4 ›› 2018, Vol. 35 ›› Issue (1): 63-68.

空间非均匀场调控H2+分子谐波辐射的研究

冯立强,刘航

辽宁工业大学

收稿日期:2016-11-09 修回日期:2016-12-08 出版日期:2018-01-28 发布日期:2018-04-04
通讯作者: 刘航

Controlling H2+ molecular harmonic radiation by spatial inhomogeneous field

Received:2016-11-09 Revised:2016-12-08 Published:2018-01-28 Online:2018-04-04

摘要/Abstract

摘要： 采用数值求解非玻恩奥本海默近似薛定谔方程，对空间非均场调控H2+分子谐波辐射及分布进行了理论研究。结果表明，激光场正向时，负向H核对谐波辐射贡献高于正向H核；激光场负向时，正向H核对谐波辐射贡献高于负向H核。激光空间位置远离原点时，谐波截止能量增大。但是当激光空间位置为负向时，负向H核对高阶谐波贡献明显被减弱。通过分析电离几率，谐波辐射时频分析图，电子波包运动对谐波辐射过程给出了解释。最后，通过叠加谐波可获得45 as超短脉冲。

关键词: 阿秒脉冲

Abstract: Controlling the molecular harmonic generation and distribution from H2+ driven by the spatial inhomogeneous field have been theoretically investigated by solving the Non-Bohn-Oppenheimer time-dependent Schrodinger equation. It shows that when the laser field is larger than zero, the contribution from the negative-H to the harmonic spectrum is higher than that from the positive-H; when the laser field is smaller than zero, the contribution from the positive-H to the harmonic spectrum is higher than that from the negative-H. The harmonic cutoff can be extended when the spatial position of the inhomogeneous field is moving away from the center. However, the contribution from the negative-H to the higher harmonic orders will be decreased when the spatial position of the inhomogeneous field is chosen to be the negative value. The ionization probabilities, the time-frequency analyses of the harmonic spectra and the time-dependent wave functions have been shown to explain harmonic emission process. Finally, by superposing a properly selected harmonics, a 45 as pulse can be produced.

Key words: attosecond pulse

中图分类号:

O562.4

冯立强刘航. 空间非均匀场调控H2+分子谐波辐射的研究[J]. J4, 2018, 35(1): 63-68.

参考文献

[1] Sansone G, Benedetti E, Calegari F, et al. Isolated single-cycle attosecond pulses [J]. Science, 2006, 314 (5798): 443-446.
[2] Uiberacker M, Uphues T, Schultze M, et al. Attosecond real-time observation of electron tunnelling in atoms [J]. Nature, 2007, 446 (7136): 627-632.
[3] Goulielmakis E, Schultze M, Hofstetter M, et al. Single-cycle nonlinear optics [J]. Science, 2008, 320 (5883): 1614-1617.
[4] Li Lin, Luo Huajiang. Broad bandwidth attosecond pulse generation using mid-infrared two color field to control quantum trajectory [J]. Chinese Journal of Quantum Electronics(量子电子学报), 2012, 29 (5): 530-535 (in Chinese).
[5] Corkum P B. Plasma perspective on strong field multiphoton ionization [J]. Phys. Rev. Lett., 1993, 71 (13): 1994-1997.
[6] Zhang J, Ge X L, Wang T, et al. Spatial distribution on high-order-harmonic generation of an H2+ molecule in intense laser fields [J]. Phys. Rev. A, 2015, 92 (1): 013418.
[7] Zhang J, Pan X F, Xia C L, et al. Asymmetric spatial distribution in the high-order harmonic generation of a H2+ molecule controlled by the combination of a mid-infrared laser pulse and a terahertz field [J]. Laser Phys. Lett., 2016, 13 (7): 075302.
[8] Zhang J, Liu H F, Pan X F, et al. Carrier envelope phase effect on the spatial distribution of high-order harmonic generation in asymmetric molecule [J]. Chin. Phys. B, 2016, 25(5): 053202.
[9] Du H, Pan X F, Liu H F, et al. Controlling the contributions to high-order harmonic generation from different nuclei of N2 with an orthogonally polarized two-color laser field [J]. Chin. Phys. B, 2016, 25(9): 093202.
[10] Li Hang, Liu Hui, Feng L Q. Spatial distribution of molecular harmonic emission from H2+ [J]. Chinese Journal of Quantum Electronics(量子电子学报) (accepted).
[11] Feng L Q, Chu T S. Nuclear signatures on the molecular harmonic emission and the attosecond pulse generation [J]. J. Chem. Phys., 2012, 136 (5): 054102.
[12] Kim S, Jin J, Kim Y J, et al. High-harmonic generation by resonant plasmon field enhancement [J]. Nature, 2008, 453 (7196): 757-760.
[13] Shaaran T, Ciappina M F, Lewenstein M. Quantum-orbit analysis of high-order-harmonic generation by resonant plasmon field enhancement [J]. Phys. Rev. A, 2012, 86 (2): 023408.
[14] Ciappina M F, Acimovic S S, Shaaran T, et al. Enhancement of high harmonic generation by confining electron motion in plasmonic nanostrutures [J]. Opt. Express, 2012, 20 (24): 26261-26274.
[15] Lu R F, Zhang P Y, Han K L. Attosecond-resolution quantum dynamics calculations for atoms and molecules in strong laser fields [J]. Phys. Rev. E, 2008, 77 (6): 066701.
[16] Burnett K, Reed V C, Cooper J, et al. Calculation of the background emitted during high-harmonic generation [J]. Phys. Rev. A, 1992, 45 (5): 3347-3349.
[17] Antoine P, Piraux B, Maquet A. Time profile of harmonics generated by a single atom in a strong electromagnetic field [J]. Phys. Rev. A, 1995, 51 (3):R1750-R1753.