Laser-field-related recombination interference in high-order harmonic generation fromCO2molecules

Controlling the Interference of Multiple Molecular Orbitals in High-Harmonic Generation

“…[4]. Recent theoretical work suggests ionization from multiple orbitals to be responsible for the intensity dependence of the minimum position [4], while other work suggests that the effect of the strong laser field on a single orbital can explain the intensity dependence [13].…”

Two-center interference during the high harmonic generation in aligned O_2 molecules

“…As a comparison, we also plot the spectral distributions in aligned CO 2 molecules at the different driving laser intensity, shown in Fig. 4 (b) [16]. They also show that the spectral region of the destructive suppression (S/S 0 < 1) can be shifted to the higher harmonic order by enhancing the driving laser intensity.…”

“…The harmonic emission from impulsively aligned CO 2 shows a special feature that the harmonic yield in some spectral region exhibits an inverted modulation versus the molecular alignment parameter, and the modulation inversion is attributed to the interference of recombining electron from the two oxygen atoms [9][10][11][12][13][14][15][16]. Boutu et al [17] even gave the phase measurement of harmonics generated in aligned CO 2 molecules, which provided proof for an interpretation in terms of destructive quantum interference.…”

“…The calculated time-dependent alignment parameters 2 cos ( ) t   [15][16] are also shown in Fig. 1 (the red dashed curves and right axis, the initial rotational temperature is taken to be 80 K).…”

“…However, the harmonic orders that are inversely modulated differed in different experiments from CO 2 molecules, and the effect of the molecular potential on the recolliding electron wave packet was treated differently in the interpretation of experimental data [9][10][11][12][13]. Therefore, we attributed such phenomena to the laser field distortion of the molecular HOMO, which should play a key role in such quantum system [16]. Moreover, the role of the multiple HOMOs effect was also proposed for the laser intensity dependence in aligned molecules recently [18][19][20][21][22][23].…”