Giant Tunable Goos–Hänchen Shifts Based on Prism/Graphene Structure in Terahertz Wave Region

We investigate the giant tunable Goos-Hänchen shifts in prism/graphene structure. It is found that large positive and negative lateral Goos-Hänchen shifts can be easily controlled by adjusting the chemical potential of the graphene, which is modulated by the external applied electric field. By using the stationary-phase method, we theoretically analyze the effect of the external applied electric field on Goos-Hänchen shifts of the proposed prism/graphene structure. Our theoretical study shows that the magnitude of the Goos-Hänchen shift is more than 200 times that of the operating terahertz wavelength. Numerical calculation results further indicate that the present structure has the potential application for the terahertz-wave switch.