Tunnel ionization of diatomic molecules by an intense CO2 laser

The non-resonant interaction of an intense nanosecond CO2 laser pulse with Hg2, N2, and H2 shows that the molecules are tunnel ionized as if they were atoms with the same ionization potentials as the molecules. Moreover, dissociation of the neutral molecule appears to be much less probable even though the dissociation energies are lower than the ionization potentials.