Controlling Rydberg-dressed four-wave mixing via dual electromagnetically induced transparency windows

Rydberg-dressed four-wave mixing (FWM) is theoretically and experimentally demonstrated with two electromagnetically induced transparency (EIT) windows generated in a Y-type Rb85 atomic configuration. Such dressing effect related to Rydberg states can lead to enhancement and suppression in the FWM process, which can be manipulated by the frequency detuning, Rabi frequency, and polarization of laser fields. Particularly, with the enhancement condition satisfied, coexisting FWM and Rydberg six-wave mixing (SWM) peaks with ultranarrow linewidth (much less than 30 MHz) are simultaneously observed. The controllable enhancement and suppression in a Rydberg-EIT medium can provide a novel nondestructive nonlinear method to investigate the spectrum involving Rydberg excitation in the atomic ensemble above room temperature.