We investigate Autler-Townes splitting in the photoelectron spectra of K_2 molecule driven by pump-probe pulses via employing the time-dependent wave packet approach.It is found that the magnitude of Aulter-Townes splitting varies with the wavelength of the intense laser pulse.In particular,the phenomenon of Aulter-Townes splitting vanishes for the far-off resonance of the pump pulse.Also,the split peaks of Autler-Townes in the case of resonant pump pulse give us an approach to directly obtaining the transition dipole moment of a molecule.
We theoretically study the statistics of photon emission of a single multi-level quantum system by employing the generating functions approach developed recently.The generalized decay constants are included in a single multi-level quantum system with quasi-degenerated levels in this work although they are normally neglected in the absence of (quasi-)degeneracies in a multi-level quantum system within the rotating wave approximation.The quantum beats,the line shapes and the Mandel's Q parameters,etc.are studied.