Numerical Simulation Of Population Transfer Of Three-level System

It is possible to prepare atoms or molecules in a selected excited state, one efficient way is to transfer population by stimulated-Raman-adiabatic-passage, but we must understand off-resonant effects in coherent excitation in order to improve the efficient of transfer.Here, we consider the transfer of population in a three-level system of stimulated-Raman- adiabatic-passage with computer analysis. We worked out the transfer efficiency with different displacement of Pump laser and Stokes laser, and then explain the importance of counter-intuitive in the process of transfer. The transfer efficiency of two-photon resonant is also worked out and the outcome demonstrates the possibility of complete transfer. We also analysis the effect of -two-photon off-resonant, single-photon off-resonant and difference of two lasers' intensity.