  We discover a new mechanism of electronic population inversion using strong
femtosecond pulses, where the transfer is mediated by vibrational motion on a
light-induced potential. The process can be achieved with a single pulse tuning
its frequency to the red of the Franck-Condon window. We show the determinant
role that the sign of the slope of the transition dipole moment can play on the
dynamics, and extend the method to multiphoton processes with odd number of
pulses. As an example, we show how the scheme can be applied to population
inversion in Na2.
