Investigation on the influence of atomic potentials on the above threshold ionization

We systematically investigate the influence of atomic potentials on the above-threshold ionization （ATI） spectra in one-dimensional （1D） cases and compare them with the three-dimensional （3D） case by numerically solving the time-dependent Schrrdinger equation. It is found that the direct ionization plateau and the rescattering plateau of the ATI spectrum in the 3D case can be well reproduced by the 1D ATI spectra calculated from the supersolid-core potential and the soft-core potential, respectively. By analyzing the factors that affect the yield of the ATI spectrum, we propose a modified-potential with which we can reproduce the overall 3D ATI spectrum. In addition, the influence of the incident laser intensities and frequencies on the ATI spectra calculated from the proposed modified potential is studied.     

联合双原子在组合脉冲辐照下的高次谐波发射

首先采用经典的“三步模型“理论,分析了一维普薛耳-特勒势(P-T势)模型原子在组合脉冲作用下的动力学行为,进而利用该组合脉冲辐照联合双原子模型,通过调节组合脉冲的场幅、相位以及设定原子的核间距,使原子有适当的电离和较大的复合效率,因而在截止位置远达Ip 8Up处获得了效率高达10-9的高次谐波发射.     

应用辛算法计算强激光场中的一维模型氢原子

采用辛算法计算并讨论了氢原子在不同峰值强度或不同脉宽下的谐波谱.     

含时量子蒙特卡罗方法研究两电子原子在强激光作用下电子的动力学行为

通过改进含时量子蒙特卡罗方法研究了一维模型双电子原 子在强激光作用下的电子动力学过程. 与准确的数值积分求解含时薛定谔方程相比, 计算得到的波包对应的量子系综中粒子的动力学变化和含时波包演化结果定性一致, 且大幅度地提高了计算效率. 根据计算得到的经典粒子系综的动力学演化行为, 分析了原子在强激光作用下的激发、电离、重散射等非线性过程.     

相对论质量修正效应对超高次谐波的影响

通过分别求解含时狄拉克方程和含时薛定谔方程, 研究了一维模型原子在相对论超强激光脉冲作用下的超高次谐波发射过程. 研究结果表明: 在弱场强条件下, 相对论的模拟结果可以退化到非相对论的结果; 随着场强的增强, 可以逐渐观察到明显的相对论质量修正效应. 此外, 根据发展的相对论的"三步"模型并结合小波时频分析方法, 分析了谐波平台的截止位置和发射效率.     

Generation of a Super Strong Attosecond Pulse from an Atomic Superposition State Irradiated by a Shape-Optimized Short Pulse

Using a linearly polarized, phase-stabilized 3-fs driving pulse of 800 nm central wavelength shape-optimized on its＇ascending edge by its an amplitude-reduced pulse irradiating on a superposition state of the helium atom, we demonstrate theoretically the generation of a super strong isolated 176-attosecond pulse in the spectral region of 93-124 eV. The unusually high intensity of this attosecond pulse is marked by the Rabi-like oscillations emerging in the time-dependent populations of the ground state and the continuum during the occurrence of the electron recombination, which is for the first time observed in this work.     

在强场电子复合过程中发现类拉比振荡

在强场原子高次谐波发射的理论计算中,我们首次发现了在电子复合过程中本该有的涉及连续态含时布居的类拉比振荡,为观察强场高次谐波的高效发射提供了一个新的信息丰富的窗口.     

纳米金膜及金壳表面局域等离激元对 上转换荧光波长的选择调控

基于贵金属表面局域等离子体共振(LSPR)调控上转换荧光的研究绝大部分集中于纳米颗粒或纳米棒,即使同一复合结构对上转换荧光(UCL)也有或增强或猝灭的截然相反的报道,而对于进一步提高上转换荧光材料的效率和强度以满足更广泛的应用需求则越来越引起人们高度关注。本文通过构筑两种纳米金/上转换纳米晶复合结构,系统研究了各自的表面局域等离激元对上转换荧光的增强和猝灭效应,基于微结构表征及对稳态、瞬态荧光光谱的分析,阐述了波长依赖的上转换荧光增强和猝灭机理。结果显示超薄纳米金壳结构对Ho~(3+)、Fe~(3+)共掺杂纳米晶的绿光发射选择性地增强了25倍,源于激发光能量与LSPR能量匹配的激发增强机制,而在覆盖有超薄纳米金膜的上转换纳米晶复合结构中却观察到了金膜引起的Er上转换荧光猝灭,同时红绿比随金膜厚度增加而增大,来自于金膜对激发光的散射、金膜的LSPR吸收带与绿光发射能级耦合引起无辐射跃迁几率增加,绿光上转换荧光强度下降相对显著,UCL寿命变短。     

一维模型原子高次谐波发射效率影响因素的研究

本文通过分析影响原子高次谐波发射效率的几个基本元素,定量地得到了如下规律:(1)高次谐波发射效率与复合时刻电子在基态和连续态上的布居乘积成正比;(2)谐波发射效率随复合电子能量的增加而急剧下降.理论解释了上述规律产生的原因.     

Internal collision double ionization of molecules driven by co-rotating two-color circularly polarized laser pulses

The double ionization process of molecules driven by co-rotating two-color circularly polarized fields is investigated with a three-dimensional classical ensemble model. Numerical results indicate that a considerable part of the sequential double ionization(DI) events of molecules occur through internal collision double ionization(ICD), and the ICD recollision mechanism is significantly different from that in non-sequential double ionization(NSDI). By analyzing the results of internuclear distan...