Tunable enhancement of spatial lateral shifts in periodic chiral metamaterials

Abstract

In this paper co-polarization spatial Goos–Hänchen (GH) shifts (Δss/λ and Δpp/λ) of periodic chiral metamaterials are investigated. The numerical results show that the enhancement of GH shifts is affected by the incident frequency, the incident angle, the period and the volume fraction of the dispersive chiral layer. For s polarized waves, GH shifts are always enhanced negatively with one Brewster angle, but two Brewster angles arise when the period is large and specific. For p polarized waves there are two Brewster angles in general, at which the GH shifts can be greatly enhanced with negative and positive peaks. More Brewster angles appear when the period is sufficiently large and specific. The transition of negatively and positively enhanced GH shifts is sensitive to large frequencies, and can be tuned by changing the frequency slightly. The transition can also be adjusted by varying the volume fraction of the dispersive chiral layer and the period of the structure.