Vacuum induced enhancement and suppression of six-wave mixing in a ring cavity

We report experimental observation of the enhancement and suppression of four-wave mixing and six-wave mixing (SWM) inside a ring cavity containing a rubidium atomic cell. g√N greatly amplifies the SWM enhancement peak and suppression dip, and the vacuum induced Kerr nonlinear phase shift results in the asymmetric phenomenon of the SWM dressing effect. Additionally, we study the power switch and the destructive interference between multi-photon processes. Such investigation results can find applications in all-optical switches and optical communications. (letter)