Wavelength-dependent study of trapping molecules in an excited electronic state of I22+ with strong laser fields

Using the B-3 Pi(+)(u) state of neutral I-2 as an intermediate state, we populate an excited electronic state, designated as (2,0), of I-2(2+) in its bound region of internuclear separation with short laser pulses. Trapping of the molecules in the (2,0) state is deduced from the disappearance of the (2,0) dissociation signal when populated at large internuclear separation, and wavelength-dependent results rule out electron localization as an alternative explanation for this disappearance. The wavelength dependence also firmly establishes the B state as the intermediate state. Moreover, simulation results are consistent with the experiments, which confirm the previously measured (2,0) potential curve. The (2,0) state correlates to the I2+ + I0+ dissociation limit and has played an important role in strong field physics. It is also the lowest lying truly bound (not metastable) state of the dication. In addition, the potential curve of the I-2(3+) ground-state manifold is measured. Finally, calculations show a general picture of the wavelength dependence for trapping molecules in potential wells using intermediate states.