Controllable ultra-narrow fluorescence and six-wave mixing under double electromagnetically induced transparency

Abstract

We report the first observation of six-wave mixing (SWM) and fluorescence signals in an electromagnetically induced transparency (EIT) window. Several remarkable advantages are described. First, multiple bright and dark states are simultaneously observed due to enhancement or suppression of the SWM signal. Second, ultra-narrow fluorescence, much narrower than the EIT window, is experimentally obtained. Third, the ultra-narrow fluorescence can also generate Autler–Townes splitting on scanning the coupling beam. Fourth, a double-peak EIT window is obtained using the nest-dressing scheme. Such studies concerning SWM and fluorescence have applications in optical switching, multi-channel communication and narrowband and long-range quantum communication.

Ultranarrow linewidth and high gain of an optical cavity with enhanced self-Kerr nonlinearity in quantum dot molecules

“…Cavity linewidth narrowing has potential applications in many fields including laser stabilization [1], metrology [2] and coherent optical communications [3,4]. A strong dispersion medium introduced into an optical cavity narrows the linewidth [5], and a linewidth 1/7 of that of the cavity has been obtained through an electromagnetically induced transparent (EIT) [6] medium [7], which is the so-called intracavity EIT [1,8].…”