Population transfer by stimulated Raman scattering with delayed pulses: Analytical results for multilevel systems

Abstract

Stimulated Raman scattering involving adiabatic passage (STIRAP) is a proven technique for population transfer in three‐level systems with strong oscillator strengths. We show that the STIRAP process should also yield high transfer efficiencies when the densities of states near the intermediate and final levels are high, provided certain criteria for the experimentally controllable parameters are met. We also show that high transfer efficiencies may even be possible when the pump and Stokes lasers can access levels outside of the three‐level system. The criteria are derived with an approach that emphasizes the adiabatic nature of the transfer process in an eigenvector of the interaction Hamiltonian that resembles a trapped state. The results are compared to density matrix calculations.