Enhancing and suppressing four‐wave mixing in electromagnetically induced transparency window

We demonstrate the enhancement and suppression of four‐wave mixing (FWM) in an electromagnetically induced transparency (EIT) window in Y‐type ⁸⁵Rb atomic system. The generated two‐photon FWM signal can be selectively enhanced and suppressed via an EIT window. The EIT of probe as well as the enhancement and suppression of FWM signals can be modified by the sequential‐cascade double dressing. The influence of different probe polarization configurations is also studied. Different polarization states of the probe laser can select different transitions among Zeeman sublevels and different dressing strengths. Copyright © 2010 John Wiley & Sons, Ltd.