Enhanced light retrieval from a memory based on interfering recoil-induced resonances

We report on the observation of efficient light storage based on recoil-induced resonances and the associated generation of forward four-wave mixing signal. We use a strong coupling beam red-detuned from the closed transition $6S_{1/2}, F=4\rightarrow6P_{3/2}, F^{\prime}=5$ of cold cesium atom and a two-mode probe beam, whose frequency can be scanned around the coupling beam frequency. First, we demonstrate the coherent phase transfer from one mode component of the probe beam to the corresponding forward generated four-wave mixing beam. We then explore the coherent nature of the stored optical information to retrieve the two-mode probe energy with an efficiency 3.5 fold higher as compared with the total retrieved energy efficiency associated with the case where each mode component of the probe acts separately. Finally, we discuss a possible application of our experimental scheme and observed effects to investigate squeezing and quantum photon correlations.