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 SSRb 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.