Department of Physics, Sharif University of Technology, P.O. Box 11365-9567, Tehran, Iran.
Department of Physics, Faculty of Basic Sciences, Tarbiat Modares University, P.O. Box 14115-175, Tehran, Iran.
J Chem Phys. 2018 Jun 21;148(23):234303. doi: 10.1063/1.5025155.
In this study, high harmonic generation from a multi-atomic nitrous oxide molecule was investigated. A comprehensive three-dimensional calculation of the molecular dynamics and electron trajectories through an accurate time-dependent density functional theory was conducted to efficiently explore a broad harmonic plateau. The effects of multi-electron and inner orbitals on the harmonic spectrum and generated coherent attosecond pulses were analyzed. The role of the valence electrons in controlling the process and extending the harmonic plateau was investigated. The main issue of producing a super-continuum harmonic spectrum via a frequency shift was considered. The time-frequency representation by means of a wavelet transform of the induced dipole acceleration provided a good insight into the distorted effects from the nonlinear processes in high harmonic emission. The effect of the chirped laser pulse on the production of broadband amplitude was justified in this model. By adjusting the optimal laser parameters to an input intensity of 2.5 × 10 W cm, an isolated 68 as pulse was generated.
在这项研究中，我们研究了一氧化二氮多原子分子的高次谐波产生。通过精确的含时密度泛函理论进行了分子动力学和电子轨迹的全面三维计算，以有效地探索广泛的谐波平台。分析了多电子和内轨道对谐波谱和产生相干阿秒脉冲的影响。研究了价电子在控制过程和扩展谐波平台中的作用。通过频率移动产生超连续谐波谱的主要问题被考虑在内。通过诱导偶极子加速度的小波变换进行的时频表示为高次谐波发射中的非线性过程的失真效应提供了很好的了解。在该模型中， justifies 了啁啾激光脉冲对宽带幅度产生的影响。通过将最佳激光参数调整到 2.5×10 W cm 的输入强度，产生了一个孤立的 68 as 脉冲。
