C. Cornaggia et P. Hering, Nonsequential double ionization of small molecules induced by a femtosecond laser field - art. no. 023403, PHYS REV A, 6202(2), 2000, pp. 3403
Nonsequential double ionization of several molecules such as N-2,CO2,C2H2,
and C3H4 in strong laser fields has been unambiguously identified from the
ion-yield measurements in comparison with a sequential ionization model in
the 10(13)-10(15) W/cm(2) laser intensity range. This effect is observed ma
inly using linearly polarized laser light. In circular polarization, nonseq
uential double ionization might be present, for instance for the C2H2 molec
ule, but with a much lower contribution than in linear polarization. The ex
perimental method allows us to detect all the double-ionization decay chann
els that are the molecular dication and the two-missing electron fragmentat
ion channels. The validity of a single-ionization tunneling model developed
for atoms has been extended to molecules, and a good agreement is observed
in laser intensity ranges where single-ionization processes take place.