Electromagnetically Induced Grating Of Four-level Atoms

One of the hot topics of interaction between light and atoms is the electromagnetically induced transparency. Electromagnetically induced grating is using electromagnetically induced transparency principle, the electromagnetically induced grating can form when one of the travelling wave field in the electromagnetically induced transparency is be replaced by the standing wave field. The propagation of the probe is perpendicular to the standing-wave, so the plane of standing wave field is similar to the classic grating plane. The probe field is the incident field.The paper reviews the electromagnetically induced grating in the three-level and N-level atomic systems, using the analytic solution study the efficiency of first-diffraction light. This paper focuses on electromagnetically induced grating in the double A-type atomic system. Through adjusting of parameters, the efficiency of first-order diffraction light achieves maximum diffraction efficiency. The paper includes:1. Through calculation, the analytic solution and the numerical solution of transmission function can obtain in the in a three A-type atomic system and in a N-type atomic system and have being compared.2. The variation of the efficiency of first-order diffraction light with parameters is discussed. The maximum diffraction efficiency of first-diffraction light can achieve in the group of established parameters.The contribution of this paper is that efficiency of first-order diffraction light can reach40%in the double A-type atomic system. However, electromagnetically induced grating in the N-level atoms can only diffract up to30%of probe energy into the first diffraction order. The first-order diffraction light diffraction efficiency is only10%in electromagnetically induced grating of in the three-level atom.