Internuclear distance effect of H2+ on the single-order harmonic enhancement

Abstract:

The effect of internuclear distance of H2+ on the single-order harmonic enhancement driven by the specific laser waveform has been studied theoretically. The results show that when the atom is driven by the specific laser waveform, the single-order harmonic enhancement can be found on the harmonic spectrum. However, when H2+ is driven by the same waveform, the single-order harmonic enhancement is related to the internuclear distance of H2+. Particularly, when H2+ is at its equilibrium position, the single-order harmonic enhancement can be found on the harmonic spectrum. When the internuclear distance of H2+ changes from 3 a.u. to 7 a.u., the single-order harmonic enhancement disappears. When the internuclear distance of H2+ is greater than 8 a.u., the single-order harmonic enhancement will reappear. Theoretical analyses show that the multichannel harmonic interference is responsible for the change of the single-order harmonic intensity.