Electrically tunable THz graphene metasurface wave retarders

Abstract Anisotropic materials with chirality or birefringence can be used to manipulate the polarization states of electromagnetic waves. However, comparatively low anisotropy natural hinders miniaturization optical components and devices at terahertz frequencies. In this study, we experimentally demonstrate that relative phase retardation a THz wave electrically controlled by integrating patterned mono- bilayer graphene onto an otherwise isotropic metasurface. Specifically, show refractive index for one orthogonal modulating graphene’s conductivity, thereby weakening capacitive coupling between adjacent meta-atoms in anisotropic manner. With monolayer graphene, 15° 81° two achieved. Maximum 90° through metasurface suggests its use as tunable quarter-wave plate. Continuous control from linear- circular-polarization may provide wide range opportunities development compact polarization-sensitive technology.