Observation of narrow Autler-Townes components in the resonant response of a dense atomic gas

TL;DR

This study experimentally observes narrow Autler-Townes doublets in dense atomic potassium vapor under conditions where the Rabi frequency is much smaller than the resonance width, revealing decoherence reduction effects.

Contribution

It reports the first observation of narrow Autler-Townes components in dense atomic gases under low Rabi frequency conditions, supported by a new theoretical model.

Findings

Observation of narrow Autler-Townes doublets in dense vapor

Reduction of atomic decoherence by strong drive field

Theoretical explanation of nonlinear processes in dense gases

Abstract

We have experimentally studied the reflection of a weak probe beam from a dense atomic potassium vapor in the presence of a strong laser field tuned to the atomic resonance transition. We have observed an Autler-Townes doublet under hitherto unexplored conditions, namely that the Rabi frequency induced by the strong laser field is much smaller than the self-broadened width of the resonance transition of the unexcited vapor. We attribute our observation to a reduction of the atomic decoherence by the strong drive field. We present a theoretical model of nonlinear processes in a dense atomic gas to explain the observed results.