Routes to Control ofH2Coulomb Explosion in Few-Cycle Laser Pulses

We have measured coincident ion pairs produced in the Coulomb explosion of ${\mathrm{H}}_2$ by 8–30 fs laser pulses at different laser intensities. We show how the Coulomb explosion of ${\mathrm{H}}_2$ can be experimentally controlled by tuning the appropriate pulse duration and laser intensity. For laser pulses less than 15 fs, we found that the rescattering-induced Coulomb explosion is dominated by first-return recollisions, while for longer pulses and at the proper laser intensity, the third return can be made to be the major one. Additionally, by choosing suitable pulse duration and laser intensity, we show ${\mathrm{H}}_2$ Coulomb explosion proceeding through three distinct processes that are simultaneously observable, each exhibiting different characteristics and revealing distinctive time information about the ${\mathrm{H}}_2$ evolution in the laser pulse.