Journal of Atomic and Molecular Physics
Population transfer in four-level ladder system assisted by dressing fields
Rui Zhang
Abstract
Even-N-level ladder system has been analyzed for population transfer by counterintuitive frequency-chirped laser pulse,in which N-2 intermediate states are strongly coupled by dressing laser field.The specific analysis for the four-level ladder system has been carried out by using a dressed-state picture,as representative for even-N-system.It is found that a well-controlled pulse area is required for complete population transfer from |1〉|4〉 if the dressing field is sufficiently strong and on resonance.And it is essential to detune the pump and Stokes laser so that one of the dressed intermediate states is on resonance,leading to the reduction of the whole system to the three-level system.