Alignment angle dependence of H2+ on spatial distribution of harmonic emission

Abstract:

The alignment angle dependence of H2+ on the spatial distribution of the molecular high-order harmonic generation (MHHG) has been theoretically investigated. The result shows that when the laser polarization direction coincides with the molecular axis, the harmonic emission follows the rules. When the laser field is larger than zero, the MHHG from the negative-H is higher than that from the positive-H; while when the laser field is smaller than zero, the MHHG from the positive-H is higher than that from the negative-H. As the alignment angle of H2+ increases, the intensities of the harmonic spectra decreases. Especially for the case of the harmonic emission from the positive-H, a faster decrease of the harmonics can be found, thus leading to the enhanced intensity difference of the harmonics from the two-H nuclei. Finally, through studying the time-frequency analyses of the MHHG and the time-dependent electronic wave functions, the reasons behind the electron motion and the spatial distribution of the MHHG from the two-H nuclei are shown and discussed.