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.

Controlled multiple spectral hole burning via a tripod-type atomic medium

“…The degree of asymmetry in the present system depends mainly on the detunings of the coupling fields. The larger the detunings of the coupling fields with large difference from each other, the more enhanced is the degree of the asymmetry in form of a From this discussion, we depict that, with appropriate choices of the detunings, our tripod system switches, from symmetric doublet (single EIT of Λ-type) to asymmetric doublet and asymmetric triplet (Fano-like) resonance and vice versa [62,64]. Thus the intensity and detunings of the coupling fields control the width of transparency window (spectral component), which is responsible for the steepness of the slope (∂n/∂ω) of normal (anomalous) dispersion which consequences time delay (advancement), see figures 2(c) and (d) for comparison.…”

Fano-like interference induced modification of Autler-Townes doublet spectrum via phase-dependent superposition of atomic states

“…The field-configuration is similar to that used in a four-wavemixing process. In a very recent work [41], AT-triplet emission spectroscopy has been employed to describe multiple colour scattering events controlled by atomic coherence and its dephasing. Asymmetric Fano-like resonance plays an important role in inherent mechanism involved with the scheme.…”