Ionization effects on field-free molecular alignment observed with high-order harmonic generation

Nuclear spin selective alignment of ethylene and analogues

“…Rotational dynamics, especially the alignment of molecules induced by strong, non-resonant laser pulses is momentarily intensively studied [5][6][7][8][9][10][11][12][13][14][15][16][17] (for a review see Refs. 18 and 19); many possible applications are explored, among them the separation of stereoisomers, 20 the control of molecular scattering, 21,22 the determination of ionization probabilities, 23 orbital imaging and high harmonics generation, [24][25][26] and x-ray scattering. 27 However, in most investigations carried out so far the role of nuclear spin on such processes is less studied although it has been shown for diatomic molecules [28][29][30] and for water 31 that different nuclear spin isomers show different rotational dynamics.…”

Asymmetric spatial distribution in the high-order harmonic generation of a H2+molecule controlled by the combination of a mid-infrared laser pulse and a terahertz field

“…Ge et al [18] investigated the HHG for the H 2 + molecule in Asymmetric spatial distribution in the high-order harmonic generation of a H 2 + molecule controlled by the combination of a mid-infrared laser pulse and a terahertz field a circularly polarized laser pulse, and found the harmonic intensity has been enhanced and a continuum spectrum can be obtained when a terahertz (THz) field is added. Guo et al [19] experimentally investigated the dependence of the harmonic yield and the CO 2 revival structure on aligning pulse intensity in the vicinity of the first half revival, and a good agreement with the calculated results was found. The electron wave packet has been used as a sensitive probe of the structure and dynamics of the ion core, thus the electron localization in the dissociation of molecules has received much attention.…”

Theoretical study of molecular electronic and rotational coherences by high-order-harmonic generation

“…ultrafast atomic, molecular and optical physics. High Harmonic Generation (HHG) is a sensitive tool to measure the coherent rotational [1][2][3][4][5][6][7][8][9] and vibrational [10,11] wavepacket dynamics [12] of a prepared molecular ensemble. Although the detection of coherent electronic wavepackets through the HHG process has been proposed in theory [13][14][15][16][17][18][19][20][21], it hitherto remained experimentally unexplored.…”