The role of atomic coherence in enhanced absorption line-profile

Abstract In this paper, we present a theoretical analysis of the burning of a narrow transparency window on the enhanced absorption spectrum of a probe laser in a triple resonance configuration visualized as a V-type plus a two-level system. The transparency window is due to coherence effects causing electromagnetically induced transparency (EIT) in a V-type system (i.e. Autler–Townes splitting plus quantum interference), for atomic vapor at a finite temperature. Additionally, the EIT window is enhanced by velocity induced population oscillation effect, velocity selective saturation effect, optical pumping effect (a source of ground state level population dynamics) and wavelength mismatch of the resonant laser fields forming a V-type configuration.