Coherent Control Of The Goos-Hanchen Shift In A Four-level Atomic Medium

In this article, we study the properties of the media which is a four-level atomic system under two strong driving fields. The optical model of the measurement of Goos-Hanchen displacement which we select is a system which includes three layers. And the middle media is the four-level atomic system which is far from resonance. Then we study how properties of dispersive-absorption of the four-level atomic system impact on Goos-Hanchen displacements.Under the controls of different detunningsΔ, the atomic medium will show different properties. And we study the dispersion-absorption relationship of the atomic medium under different detunningsΔ. Then we analysis the changes of the Goos-Hanchen displacements with the changes of the incident angles, with the casesΔ>0 andΔ<0 under controls of separate parametersδω1. We find whenδω1=Δ/2, the Goos-Hanchen displacements of the reflected light of and the transmitted light are completely same. The result of the change is same with that in Electromagnetically Induced Transparency medium. At the same time, we find whenΔ>0, the Goos-Hanchen displacements of the probe light are bigger than that in the caseΔ<0. However, whenΔ<0, we can get great Goos-Hanchen displacements with a little incident angle.And we can change the properties of the medium with the changeΔ>0 toΔ<0, when we don't change the detuningδω1Finally, we study the changes of the Goos-Hanchen displacements with he thickness of the media and detunings of the cavity. Then according to the dispersion-absorption relationship under different conditions, we analysis the reasons of the changes of Goos-Hanchen displacements.