Two-dimensional electromagnetically induced grating via spontaneously generated coherence and incoherent pump

Abstract

A new scheme for two-dimensional (2D) electromagnetically induced grating is proposed based on spontaneously generated coherence in a Λ-type atomic system, in which the atom interacts with two orthogonal standing-wave fields and an incoherent pumping field. Due to spatial periodical modulation, the zero absorption or even gain accompanied with large dispersion is obtained in atomic medium, and electromagnetically induced grating is formed. Thus the weak probe field could be diffracted into first-order or high-order directions with high efficiency. The diffraction feature and efficiency of the gratings could be adjusted by the probe field detuning, the interaction length, the incoherent pumping field intensity, and the relative phase as well. The scheme of 2D grating we presented may have some potential application in beam splitting and all-optical switching.