Expanded concept of the adiabatic population transfer using dressed states

We investigate several configurations for complete population transfer on the basis of the dressed state picture in a three-level system. This picture allows us not only to confirm an atom staying in the only dark state all the time under the well-known stimulated Raman adiabatic passage but also to find the considerably different dynamics from the conventional adiabatic process in cases where the pulses are significantly overlapped or concurrent (optimal detuning method). We expand the concept of the adiabatic process in order to explain all these cases.