Laser Induced Spatial Inhomogeneous Field Even Harmonic Generation And Spatial Imaging

In this paper,we solve studied the modulation effect of the spatial inhomogeneous field inhomogeneous field produced by single and double tip gold nanostructures.The main contents are as follows:(1)By studying the spatial inhomogeneous field generated by single and double tip gold nanostructures with a laser pulse of 800 nm,we compared the high order harmonics produced under single and double tip gold nanostructures,and found that the high order harmonic energy of spatial inhomogeneous field produced by single and double tip structure increases and the cutoff energy increases under the action of linear polarization laser field.Even harmonics can not be observed under action of double tip.However,odd and even harmonics are observed under the spatial inhomogeneous antisymmetric field produced by single tip gold nanostructures.Based on the time-frequency analysis and wave-packet evolution of the high-order harmonics generated in two kinds of spatial inhomogeneous fields.(2)We calculated that cutoff position of high order harmonics of hydrogen atoms when hydrogen atoms were placed at the intervals of 1 a.u.from-40 a.u.to 40 a.u.from single and double gold nanostructures under different spatial inhomogeneous parameters.(3)The spatial imaging of high order harmonics produced by single tip gold nanostructures and neon atoms is simulated by solving the one-dimensional Schr(?)dinger equation.We find that the difference is that the spatial imaging of high order harmonics of neon atoms has a secondary platform structure comparing with the spatial imaging of high order harmonics.