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

Abstract

The polarization properties of high-order harmonic generation (HHG) in the two-color circularly polarized laser fields are investigated by numerically solving the two-dimensional time-dependent Schrödinger equation. By adding a wavelength of 1600-nm right-circular-polarized field to an 800-nm left-circular-polarized field, HHG is simulated from a real model of neon atom with p orbital, but not from a hydrogen-like atom model with s orbital. The orders of 3n+1 can be selected while the orders of 3n+2 are suppressed by adjusting the intensities of the two pulses. The physical mechanism is analyzed by time–frequency analysis and semiclassical model.

Molecular photoelectron momentum and angular distributions of N2 molecules by ultrashort attosecond laser pulses*

“…With the rapid advances of ultrashort laser technology, [1][2][3] electronic dynamics in atoms and molecules on attosecond (10 −18 s) time scales has attracted great attention. [4][5][6][7][8][9][10][11][12] Recently, attosecond pulses with a duration of 43 as have been achieved by Gaumnitz et al, [13] which can track electronic motion. Time-resolved photoelectron momentum and angular distributions based on the pump-probe techniques has been used as an efficient tool to investigate molecular reaction dynamics.…”

An improved method for the investigation of high-order harmonic generation from graphene*

“…High-order harmonic generation (HHG) from atomic and molecular gases [1][2][3][4] has been a significant research topic in recent decades due to broad applications, such as diffractive imaging, [5] extracting of structural information of atoms or molecules, [6][7][8][9][10][11][12] probing magnetic dynamics. [13] More importantly, we can construct untrashort attosecond (as) pulses from harmonics, [14][15][16][17][18][19] which is an important tool for observing and controlling the ultrafast electronic dynamics in atoms and molecules.…”

Role of potential on high-order harmonic generation from atoms irradiated by bichromatic counter-rotating circularly polarized laser fields*

“…When an atom is irradiated by such an intense ultrashort laser pulse, the ultra-wide-band (from ultraviolet to x-ray) coherent high-order harmonic generation (HHG) can be carried out. [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18] HHG has been applied in the attosecond science [19][20][21] and nonlinear optics in the XUV region. [22] The harmonic spectrum from atoms in the linearly polarized laser pulse presents typical characteristics: as the harmonic order increases, the intensity of the first few order harmonics drops rapidly, and then a so-called "plateau" appears, the harmonic intensity which changes little, and there is a cut-off (beyond this energy the harmonic intensity decreases rapidly) at the end of the plateau.…”