Coherent manipulation of Goos–Hänchen shifts by forward and backward currents of complex conductivity in chiral medium

The birefringence of reflection and transmission as well as their corresponding Goos-Hänchen shifts are investigated with complex conductivity in a four level chiral atomic medium. The left circularly polarized (LCP) beam and right circularly polarized (RCP) beam obey the normalization condition |R(R,L)|+|T(R,L)|=1 with forward and backward currents as well as coupled driving fields parameters at the interface of a lossy chiral medium of |A(R,L)|≃0 and polystyrene. For the birefringent transmission, the positive GH-shifts are reported while for the birefringent reflection, the negative GH-shifts are measured. The maximum GH-shift in reflections of RCP and LCP beams is measured to Sr(R,L)=-10λ and that in the transmission is measured to St(R,L)=10λ with forward and backward currents of complex conductivity. Furthermore, maximum values of GH-shifts in reflection and transmission of LCP beams are calculated to ±40λ and RCP beams are calculated to ±10λ with control field Rabi frequency and backward current variation. The results indicate possible uses in the designing of optical and conductive sensors.