Spatial and angular shifts of terahertz wave for the graphene metamaterial structure

By considering an attenuated total reflection structure containing graphene-based hyperbolic metamaterial, we investigate the effect of surface plasmon (SP) resonance on Goos-Hanchen (GH) and Imbert-Fedorov (IF) spatial and angular shifts in the reflection of terahertz wave. It can be found that the spatial and angular shifts of the p-wave beam are giant near the plasmon resonance: the spatial GH shift can be two orders of magnitude greater than the wavelength, the angular GH shift might be several hundred or even thousands greater than the angular spread, and the IF shift may be greater than the largest values reported ever. We also find that the shifts can be controlled by manipulating the voltage applied to the graphene via exterior gate, and a large modulation bandwidth (about dozens of THz) can be achieved. Based on the giant and tunable shifts, an alternative SP sensing scheme can be provided and the sensitivity of SP sensors can be improved significantly.