Two-dimensional electromagnetically induced cross-grating in a four-levelN-type atomic system

We propose a scheme for a two-dimensional (2D) electromagnetically induced cross-grating (EICG) in a four-level N -type atomic system. By employing standing-wave fields interacting with the atomic system, the absorption and dispersion of the probe field will change with the spatial periodical modulation. The first-order diffraction intensity sensitively depends on the parameters (the probe detuning, and the amplitude and detuning of the standing-wave fields), and can reach its maximum on varying the system parameters. The present studies may be instructive to design new devices in all-optical switching and optical imaging.