Frequency dependence of ionization for H2+H2+ in linearly polarized laser fields

•The total ionization rate increases as the laser frequency decreases.•The maximal asymmetry parameter increases as the laser frequency increases.•Phase shift of asymmetry parameter emerges for different laser frequencies.

The influence of laser frequency on the ionization of H2+H2+ in few-cycle linearly polarized laser fields is investigated by numerically solving the time-dependent Schrödinger equation. It was found that the distribution of the electric field changes as the laser frequency changes. When the laser frequency is relatively small or the laser intensity is relatively strong, the total ionization is relatively large. With certain increase of the laser intensity, the increases of the total ionization rate for all frequencies are almost the same. For a fixed laser frequency, the total ionization rate increases more slowly for higher laser intensity. The asymmetry parameter describing asymmetry degree under different laser frequencies is also investigated. We found phase shift of asymmetry parameter emerges for different laser frequencies. The maximal asymmetry parameter increases as the laser frequency increases.