利用阿秒激光追踪和控制原子分子内部电子的运动(英文)

TRACING AND STEERING ELECTRON MOTION INSIDE ATOMS AND MOLECULES BY ATTOSECOND PULSES

随着强激光技术的快速发展,在物质与激光相互作用下,实验上发现了很多新奇的物理现象。这些现象成功地被各种理论模型和数值模拟所解释和证明。一种很重要的现象就是所谓的高次谐波产生:在原子和分子与强激光相互作用时,能够放出能量为基频光子能量几倍到几百倍的大能量光子。在实验上,人们已经可以通过合成截止频率附近的几个谐波来产生脉冲长度在阿秒量级的激光脉冲(1阿秒=10^(-18)s)。阿秒脉冲的获得开启了超快科学一个全新的领域:人们可以在电子运动的自然时间尺度上去探测和操控原子分子内部电子的运动,这是继飞秒科学后人们操控微观世界物质运动的又一大飞跃。在本文中,我们就最近几年我们在理论上所开展的阿秒物理做一个简单的综述,重点强调利用阿秒光去控制电子的电离动力学以及探测分子内部电子运动。

With the fast development of intense laser technologies, a lot of new phenomena in laser-matter interactions have been experimentally observed and successfully explained by various theories and simulations. One of the specular processes is high-order harmonic generation （HHG）, in which atoms and molecules can emit photons with energies equal to multiple of the fundamental laser photon energy. By synthesizing several neighboring orders of HHG spectra near its cutoff, experimentalists have been able to generate laser pulses of duration in the attosecond time scale （1 as = 10^-18 s）. The availability of attosecond pulses has opened a drastically new regime of ultrafast sciences, where it is possible for scientists to trace and control the motion of electrons on its natural scale. After the fruitful developments of femtosciences in the last two decades, the newly opened attosecond science is another big jump of human being to understand and control the internal dynamics of atoms and molecules. In this paper, we will give a brief review of what we have done in recent years, especially about tracing and controlling the electronic motion of atoms and molecules by attosecond pulses.