Modulation of High-Order Harmonic Generation from a Monolayer ZnO by Co-rotating Two-Color Circularly Polarized Laser Fields

Abstract

By numerically solving the two-dimensional semiconductor Bloch equation, this paper studies the high-order harmonic emission of a monolayer ZnO under the driving of co-rotating two-color circularly polarized laser pulses. By changing the relative phase between the fundamental frequency field and the second one, it is found that the harmonic intensity in the platform region can be significantly modulated. In the higher order, the harmonic intensity can be increased by about one order of magnitude. Through time-frequency analysis, it is demonstrated that the the emission trajectory of monolayer ZnO can be cotrolled by the relative phase, and the harmonic enhacment is caused by the second quantum trajectory with the higher emission probability. In addition, near-circularly polarized harmonics can be generated in the co-rotating two-color circularly polarized fields. With the change of the relative phase, the harmonics in the platform region can be altered from left-handed near-circularly polarization to right-handed one. Our results can obtain high-intensity harmonic radiation with an adjustable ellipticity, which provides an opportunity for the synthesis of circularly polarized attosecond pulses.

Tunable spectral continuous shift of high-order harmonic generation in atoms by a plasmon-assisted shaping pulse

“…High-order harmonic generation (HHG) [1][2][3][4][5][6][7][8][9] serves as a potent avenue for generating coherent radiation in the short-wave spectrum, with applications extending from the infrared to the XUV and even the soft x-ray range (1-30 nm). [10][11][12] This property makes high harmonics an invaluable source of light, particularly for producing attosecondduration pulses.…”

Imagining density distribution of molecular orbitals in IR+XUV co-rotating circular laser fields by frequency-domain theory

“…Compared with the two-color linearly polarized laser fields, the two-color circularly polarized laser fields provide an additional parameter: relative helicity. Especially, the so-called bicircular laser fields are composed of two coplanar circularly polarized laser fields with different frequencies and the same or opposite helicities, where these fields have raised increasing interest since it was found experimentally that HHG and attosecond pulses generated in the counterrotating two-color (CRTC) fields are circularly polarized [23][24][25][26]. In recent years, the CRTC fields and corotating twocolor (CoRTC) fields have been used to control nonsequential double ionization (NSDI) [27,28], investigate nonadiabatic offsets of the initial electron momentum distribution in strongfield tunnel ionization [29], and observe experimentally subcycle interference structures in the photoelectron momentum distributions (PEMDs) [30,31], etc.…”

Optimization of extreme ultraviolet vortex beam based on high harmonic generation

“…[17][18][19] Due to the emitted high harmonics containing information about the interaction and electronic dynamics, HHG has been introduced into different systems, including gases, [20] plasmas, [21] and solids. [22][23][24][25][26] The HHG process has also been studied extensively in theory and experiment for generating XUV vortices, which has emerged as an important research area. [27][28][29][30][31][32][33] Researchers have made significant progress in understanding and manipulating XUV vortex beams generated through the HHG process.…”