Atomic dephasing and coherence controlled tuning of the triple color scattering light using Autler–Townes triplet emission spectroscopy

Abstract

This study shows atomic dephasing and coherence controlled tuning of a triple color scattering light from a four-level atomic system into the ones of single and double color when the system is cyclically coupled with one microwave field and two optical fields. The scattering light with the symmetric double resonance in the latter case tunes into two distinct features of the asymmetric Fano-like resonance using relative phase of the coupling fields and vice versa. The asymmetric resonance, in each case, agrees excellently with the original formulation of Fano (1961 Phys. Rev. 124 1866). The coherence tuning of the resonances, caused by the constructive interference effect in the spectrum, is analyzed analytically. Distinct in the technique, we further show atomic dephasing-induced tuning of the symmetric double and asymmetric single Fano-like resonance into a Lorentzian like statistical behavior. Upon adjusting the relative amplitude of the coupling fields in favor of the resonance tuning, the triple color scattered light is controlled from a sharpened central single and broadened sides double line through central broadened single and sides sharpened double line.