Electron dynamics and harmonics emission spectra due to electron oscillation driven by intense laser pulses
Electron dynamics and harmonics emission spectra due to electron oscillation driven by intense laser pulses
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DOI：
10.1063/1.2402506
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发表时间：
2006-12
影响因子：
2.2
通讯作者：
Youwei Tian;Wei Yu;F. He;Han Xu;Vinod Senecha;D. Deng;Yi Wang;Ruxin Li;Zhi‐zhan Xu
中科院分区：
文献类型：
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作者：
Youwei Tian;Wei Yu;F. He;Han Xu;Vinod Senecha;D. Deng;Yi Wang;Ruxin Li;Zhi‐zhan Xu
采用单电子模型，研究了强激光脉冲驱动下电子振荡的动力学和谐波发射谱。数值分析了谐波辐射的谱分布和角分布，表现出与低场情况下明显不同的特征。对于足够强的驱动激光脉冲，高次谐波辐射是可能的。在不同偏振条件下，观察和分析了光谱的复杂移位和展宽结构。对于真实的脉冲光子束，辐射的光谱对于后向辐射是红移的，对于前向辐射是蓝移的，并且注意到光谱展宽。这是由于在激光脉冲期间电子的纵向速度发生了变化。这些效应在更高的激光强度下更加明显，从而产生更高的谐波，最终导致连续的光谱。数值模拟进一步表明，增加激光脉冲宽度可以限制高次谐波辐射的展宽。光谱的复杂移位和展宽可以用来表征超短超强激光脉冲和研究电子的超快动力学。(C)2006年美国物理研究所。
The dynamics and harmonics emission spectra due to electron oscillation driven by intense laser pulses have been investigated considering a single electron model. The spectral and angular distributions of the harmonics radiation are numerically analyzed and demonstrate significantly different characteristics from those of the low-intensity field case. Higher-order harmonic radiation is possible for a sufficiently intense driving laser pulse. A complex shifting and broadening structure of the spectrum is observed and analyzed for different polarization. For a realistic pulsed photon beam, the spectrum of the radiation is redshifted for backward radiation and blueshifted for forward radiation, and spectral broadening is noticed. This is due to the changes in the longitudinal velocity of the electron during the laser pulse. These effects are much more pronounced at higher laser intensities giving rise to even higher-order harmonics that eventually leads to a continuous spectrum. Numerical simulations have further shown that broadening of the high harmonic radiation can be limited by increasing the laser pulse width. The complex shifting and broadening of the spectra can be employed to characterize the ultrashort and ultraintense laser pulses and to study the ultrafast dynamics of the electrons. (c) 2006 American Institute of Physics.