Coulomb potential influence in the attoclock experimental scheme

Coulomb potential may induce a significant angular offset to the two-dimensional photoelectron momentum distributions for atoms subject to strong elliptically polarized laser fields.In the attoclock experiment,this offset usually cannot be easily disentangled from the contribution of tunneling delay and poses a main obstacle to the precise measurement of tunneling delay.Based on semiclassical calculations,here,we propose a method to extract the equivalent temporal offset induced solely by Coulomb potential(TOCP)in an attoclock experiment.Our calculations indicate that,at constant laser intensity,the TOCP shows distinctive wavelength dependence laws for different model atoms,and the ratio of the target atom’s TOCP to that of H becomes insensitive to wavelength and linearly proportional to(2Ip)?3/2,where Ip is the ionization potential of the target atom.This wavelength and Ip dependence of TOCP can be further applied to extract the Coulomb potential influence.Our work paves the way for an accurate measurement of the tunneling delay in the tunneling ionization of atoms subject to intense elliptically polarized laser fields.     

基于MATLAB在玻璃杯上凸显唯一清晰指纹的动态模拟

将MATLAB的数值计算及图形功能,用于模拟装满水的玻璃杯上凸显唯一明亮清晰指纹的现象,通过模拟图像分析了指纹成像的"明亮清晰性"和"唯一性"问题.分别讨论了指纹到水面的距离,玻璃杯的厚度等因素对该现象的影响,并且运用MATLAB进行最小二乘法拟合,建立了指纹到水面距离与出射光线到玻璃杯外壁距离的线性函数关系.