Enhancement of the Goos–Hänchen shift by electromagnetically induced transparency with amplification

The manipulation of the Goos–Hänchen (GH) shifts of the reflected and transmitted probe beams through a cavity containing ∆-configuration artificial or realistic atomic medium is investigated. Adjusting the coherent control fields of atomic medium, the electromagnetically induced transparency with amplification (EITA) can be yielded. When the frequency of probe beam is around EITA, the negative as well as positive GH shifts of the reflected and transmitted probe beams can be greatly enhanced by EITA. Meantime, the GH shift can be switched between the considerably large positive and negative values by adjusting the collective phase of the external fields.