When one extends the conventional stimulated Raman adiabatic passage method of population transfer; involving a pump pulse preceded by a Stokes pulse, to situations in which the pump (or pump and Stokes) interaction involves a two-photon transition, there occur unavoidable dynamic Stark shifts which prevent maintenance of the relevant resonance conditions. Such shifts can prevent the desired population transfer. We show, through numerical modeling and analytic considerations, that the detrimental effects of dynamic shifts can be compensated by a suitable choice of (static) detunings of the carrier frequencies of the two pulses, so that population transfer can be achieved. We present simple analytic expressions for bounding the range of detunings for which population transfer can occur, and we present numerical results supporting the simple picture of the two-step linewidth. We illustrate these remarks by considering specific examples.

• Received 11 May 1998

DOI:https://doi.org/10.1103/PhysRevA.58.4691