We propose a dynamic pump-control scheme to manipulate the molecular predissociation process of NaI using two color few-cycle laser pulses. We excite the NaI molecule with a pump pulse (648 nm, 35 fs) and employ another control laser pulse (7.53 μm, 50 fs) to modify the molecular potential energy surfaces (MPESs) of NaI in the coupling zone. The intersection of the two diabatic MPESs will move in opposite directions due to the nonresonant dynamical Stark effect (NRDSE) introduced by the control pulse. The final dissociation channels, i.e., ionic channel and covalent channel, can be well controlled by tuning the carrier-envelope phase (CEP) and the time delay of the control pulse. We find that the percentage of the covalent channel can reach ∼91.3$\%$ when the CEP of the control pulse is taken to be ∼0.45π at a delay time slightly before the adiabatic coupling zone. On the contrary, a minimum percentage of 18.3$\%$ can be obtained at CEP ∼1.79π at a delay time slightly after the adiabatic coupling zone.

• Received 12 December 2011

DOI:https://doi.org/10.1103/PhysRevA.85.023406