Restraint of spatial distribution in high-order harmonic generation from a model of hydrogen molecular ion

Abstract

The spatial distribution in high-order harmonic generation (HHG) is theoretically investigated by using a few-cycle laser pulse from a two-dimensional model of a hydrogen molecular ion. The spatial distribution in HHG demonstrates that the harmonic spectra are sensitive to the carrier envelope phase and the duration of the laser pulse. The HHG can be restrained by a pulse with the duration of 5 fs in the region from the 90th to 320th order. This characteristic is illustrated by the probability density of electron wave packet distribution. The electron is mainly located near the nucleus along the positive-x direction from 3.0 o.c. to 3.2 o.c., which is an important time to generate the HHG in the plateau area. We also demonstrate the time-frequency distribution in the region of the positive-and negative-x direction to explain the physical mechanism.

Selection of right-circular-polarized harmonics from p orbital of neon atom by two-color bicircular laser fields*

“…High-order harmonic generation (HHG) which is a useful tool to monitor quantum dynamics has been intensively investigated. [1][2][3][4][5][6][7] HHG could be used to produce attosecond pulse [8][9][10][11][12] that is a powerful tool to probe, track, control the dynamics of electron in ultrafast process. [13][14][15][16] Recently, linearly polarized attosecond pulse could be obtained from linear polarized harmonics in experiments, [17,18] and the HHG process is well described by semiclassical three-step model.…”

Backward rescattered photoelectron holography in strong-field ionization

“…When an atom or molecule is exposed to a strong laser field, the electron in a bound state may be tunneling ionized through the barrier formed by the Coulomb potential of the parent ion and the electric field of the laser pulse, which is the basis of other strong-field processes. [1][2][3][4][5][6][7][8][9] During the laser pulse, the electron wave packets (EWP) ionized at different times with the same final momentum will interfere with each other due to the coherent nature. Therefore, various interference patterns appear in the final photoelectron momentum distribution (PMD).…”