Role of dressed-state interference in electromagnetically induced transparency

Electromagnetically induced transparency (EIT) in three-level systems uses a strong control laser on one transition to modify the absorption of a weak probe laser on a second transition. The control laser creates dressed states whose decay pathways show interference. We study the role of dressed-state interference in causing EIT in the three types of three-level systems-lambda (Lambda), ladder (Xi), and vee (V). In order to get realistic values for the linewidths of the energy levels involved, we consider appropriate hyperfine levels of Rb-87. For such realistic systems, we find that dressed-state interference causes probe absorption-given by the imaginary part of the susceptibility-to go to zero in a A system, but plays a negligible role in Xi and V systems. (C) 2016 Elsevier B.V. All rights reserved.