Dynamically controllable two-color electromagnetically induced grating via spatially modulated inelastic two-wave mixing

Abstract

A scheme for controlling two-color electromagnetically induced grating (TCEIG) in a coherently prepared cold atomic ensemble with a four-level inverted Y-type configuration is proposed via exploiting inelastic two-wave mixing process. By adding an intensity mask behind the auxiliary control field, the transmission functions of the incident probe field and the generated signal field are modulated periodically, thereby leading to the formation of TCEIG. Using experimentally achievable parameters, both the probe and signal fields with different frequencies can be simultaneously diffracted into high-order diffractions. It is found that the diffraction efficiencies of TCEIG, especially the first-order diffraction efficiency, can be significantly improved via adjusting the detunings of the probe and signal fields. Furthermore, it is also demonstrated that the diffraction of TCEIG can be manipulated via tuning the intensity and detuning of the control field. Finally, we investigate the influence the phase mismatch on the diffraction of TCEIG. It is shown that the diffraction pattern of the probe field is rather robust against the phase mismatch, while the diffraction intensities of the signal field are suppressed by the phase mismatch. Our scheme may provide a possibility for the all-optical control of optical switch and wavelength division multiplexing.