Tunable and switchable bifunctional meta-surface for plasmon-induced transparency and perfect absorption

Tunable multi-function metasurfaces have become the latest research frontiers in planar optics. In this study, a dynamically tunable plasmon-induced transparency (PIT) structure based on a graphene split-ring resonator and graphene ribbon is proposed. The influences of the structural parameters and graphene Fermi energy on the PIT response were investigated both analytically and numerically simulations. The inclusion of an additional vanadium dioxide (VO 2 ) substrate layer enables the metasurface to achieve dynamic switching between PIT and perfect absorption using the phase change property of VO 2 . The new metasurface device exhibits the PIT effect when the VO 2 layer is in an insulating state and acts as a perfect absorber when it is in a metallic state. Moreover, the response of the two functions can be easily adjusted dynamically by changing the Fermi energy of graphene. In addition, both functions were highly sensitive to changes in the ambient refractive index. The results of this work have potential applications in slow-light devices, optical switches, modulators, perfect absorbers, highly sensitive sensors, and multifunctional devices.