The effects of pulse width, laser wavelength and laser intensity on the state populations of NaI molecule driven by a pump-probe pulse were studied via employing the time-dependent wave packet approach. Wave packet moves periodically with roundtrip time 1000 fs. That the wave packet bifurcates in the crossing region affects state populations. The excitation probability increases and dissociation probability decreases with increasing pulse width. The excitation probability approaches the maximum at the resonance pump wavelength 318 nm, and the d...
