氢原子在少周期强激光场中阈上电离的电子波包干涉图像  

Electron wave packet interference images in above-threshold ionization of hydrogen atoms by few-cycle intense laser fields

作　　者：郭志坚 孙乾 GUO Zhi-jian;SUN Qian(College of Electrical Engineering,Longdong University,Qingyang 745000,China)

机构地区：[1]陇东学院电气工程学院

出　　处：《中国光学》2019年第6期1376-1384,共9页Chinese Optics

基　　金：国家自然科学基金资助项目(No.11565018);甘肃省教育厅高等学校创新能力项目(No.2019A-112);陇东学院博士基金资助项目(No.XYBY1601);陇东学院青年科技创新项目(No.XYZK1706)~~

摘　　要：采用电子波包干涉方法研究了长程库仑势以及再散射电子对氢原子在少周期强激光场中阈上电离的影响。首先,利用强场近似及Coulomb-Volkov近似结合时间窗函数,模拟了氢原子在波长为800 nm且脉宽为5 fs的线性极化激光场中单电离的周期内干涉及周期间干涉图像,发现在长程库仑势作用下周期内干涉及周期间干涉共同作用形成了二维动量谱中的部分扇形结构条纹,其余部分扇形条纹的形成与再散射电子有关。然后,通过数值求解含时薛定谔方程计算了深度隧穿电离机制下氢原子的二维动量谱,在二维动量谱中出现了明显的径向条纹。研究结果表明,该径向条纹的产生与长程库仑势无关,是再散射电子波包干涉形成的。By using electron wave packet interference methodology,the effects of long-range Coulomb potential and rescattering electrons on the above-threshold ionization of hydrogen atoms in few-cycle intense laser field are investigated.Firstly,using the strong field approximation and Coulomb-Volkov approximation combined with the time window function,the intra-and inter-cycle interference images of hydrogen atoms in a linearly polarized laser field with a wavelength of 800 nm and a pulse width of 5 fs are simulated.It was found that a part of fanlike structure in 2D momentum spectra is formed by the interplay of inter-cycle and intra-cycle interferences under the action of long-range Coulomb.Subsequently,the first principle solution of the Time-Dependent Schrodinger Equation(TDSE)is used to calculate the 2D momentum spectrum of hydrogen atoms under the deep tunneling ionization mechanism.It was found that there are some abvious radial fringes in the 2D momentum spectrum.The results show that the radial fringes are formed by the interference of the rescattering electron wave packets,which are independent of the long-range coulomb potential.

关 键 词：阈上电离 周期内干涉 周期间干涉 二维动量谱 光电子能谱 

分 类 号：O436[机械工程—光学工程]