  The Stimulated Raman Adiabatic Passage (STIRAP) procedure is a robust and
complete population transfer method which have various application in chemistry
and atomic physics. Here, we study the effects of one-photon detuning,
transition time, pulse width, and pulse delay parameters on the population
transfer via STIRAP and b-STIRAP techniques. Moreover, the impact of the field
amplitude which decreases the population transfer has been analyzed and it is
shown that in b-STIRAP, the robustness of the complete transition can be
improved by decreasing the field amplitude in the single-photon resonance
condition.
