动量空间含时伪谱方法及其在强场原子物理中的应用

项目名称： 动量空间含时伪谱方法及其在强场原子物理中的应用

项目编号： No.11247024

项目类型： 专项基金项目

立项/批准年度： 2013

项目学科： 物理学II

项目作者： 陈基根

作者单位： 台州学院

项目金额： 20万元

中文摘要： 基于强激光驱动下的电子波包在动量空间布居局域的特点，采用含时广义伪谱方法，利用数值技术结合解析求解的方案精确处理动量空间原子势的奇点问题，调节映射参数优化格点分布，快速、准确地模拟惰性气体原子在中红外强激光场中的动力学行为。采用该自主开发的程序包，借助简并里德堡态的相干干涉，调控里德堡电子的初始布居分布，在超短中红外强激光脉冲驱动下，实现高次谐波谱的选频增强，进而生成高效超短的孤立阿秒脉冲；探究库仑势对阈上电离谱及光电子角分布的影响，系统模拟实验观测到的中红外激光脉冲低能阈上电离谱的hump结构，阐明其产生的量子效应，并揭示新的低能干涉特性。本项目的开展，有助于推进强激光脉冲与原子相互作用的数值模拟研究，加深人们对原子在中红外激光脉冲辐照下产生的相关超快物理过程的理解。

中文关键词： 含时伪谱方法；阈上电离；高次谐波；阿秒脉冲；

英文摘要： The time-dependent generalized pseudo-spectral method is adopted to quickly and acuurately simulate the dynamic behaviors of Inert gas atoms irradiated by the mid-infrared strong laser pulse,because the electronic wave packet driven by an intense laser field is located in a local momentum space. Here, the numerical technology combined with the analytic solution scheme is used to accurately deal with the singularity problem of the atomic potential in momentum space, and the mapping parameter is adjusted to optimize the grid point distribution. Taking advantage of the coherent interference of the degenerate Rydberg states, we hope to realize the frequencies-selected enhancement of high-order harmonic generation from an mid-infrared ultr-short laser pulse by changing the initial population of the Ryderg electron, and produce an ultra-short isolated attosecond pulse with high intensity. In addition, we will also simulate the hump low-energy structures in the above-threshold ionization spectra, which are observed in recent experiments on the photoionization of atoms in strong mid-infrared laser fields, and then clarify its quantum effects and reveal new interference structures in low energy region. The development of this project will contribute to the investigation of the numerical simulation of atoms interacting

英文关键词： Time-dependent pseudo-spectral method；Above-threshold ionization；High-order harmonic generation；Attosecond pulse；