In this paper, we study the electromagnetically induced grating via spontaneous emission induced coherence (SIC) in a four-level quantum system consisting of a Rydberg state. The quantum system interacts with a weak probe light and a strong coupling light with standing wave pattern. We find that under presence of SIC, the amplitude and phase modulations of the medium can be controlled when we tune the detuning of the coupling light. Here, we realize that by tuning the amplitude and phase modulations of the medium, the energy of probe light can be transferred from zero order to high order of grating, respectively. In this case, the switching from amplitude grating to phase grating is possible when we adapt the optical parameters of the medium. Our proposed model may have potential applications in quantum information processing.

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