Expanded concept of the adiabatic population transfer using dressed states

We investigate several configurations for complete population transfer on t he 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 t he time under the well-known stimulated Raman adiabatic passage but also to find the considerably different dynamics from the conventional adiabatic p rocess 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. [S1050-2947 (99)05002-7].