Polarization enhancement and suppression of four-wave mixing in multi-Zeeman levels

Polarization dependence of the enhancement and suppression of four-wave mixing (FWM) in a multi-Zeeman level atomic system is investigated both theoretically and experimentally. A dressing field applied to the adjacent transition can cause energy level splitting. Therefore, it can control the enhancement and suppression of the FWM processes in the system due to the effect of electromagnetically induced transparency. The results show that the pumping beams with different polarizations select the transitions between different Zeeman levels that, in turn, affect the enhancement and suppression efficiencies of FWM.     

Enhanced or suppressed six-wave mixing in a five-level atomic system

We show the enhancement and suppression of a six-wave mixing (SWM) signal in the electromagnetically induced transparency in a five-level ⁸⁵Rb atomic system. The results show the Autler—Townes splitting and the enhancement or suppression of SWM, which are caused respectively by a self-dressing effect and by an external dressing effect in the presence of mutual dressing between two SWM signals. In addition, we observe the polarization dependence of the enhancement and suppression of the SWM signals.