▎ 摘　　要

In this work, we propose a tunable hyperbolic graphene-polar dielectric metamaterial in the far-infrared range. Here, we employ LiF as a strongly dispersive photonic material which can support surface plasmon polariton within its polaritonic gap. The proposed metamaterial has been analyzed using effective medium approximation (EMA) and transfer matrix method (TMM). It is found that the characterization of the hyperbolic behavior and reflection coefficient of the proposed metamaterial can be effectively controlled by Fermi energy, number of graphene layers and thickness of LiF. According to the results, the hyperbolic bandwidth broadening is possible by increasing Fermi energy, number of graphene layers and decreasing LiF thickness. Furthermore, we have shown fully controllable reflective filtering property of the proposed metamaterial using EMA and TMM. It can be clearly visualized that for thick LiF, effective medium approximation results in complete validation in calculation of the reflection coefficient. This is demonstrating by comparison between the reflection coefficient of the proposed metamaterial calculated using EMA and TMM. We believe that the proposed graphene-polar dielectric metamaterial offers a potential strategy for fine tunning the hybridized surface plasmon phonon polariton in the far-infrared region towards high performance, tunable and active metamaterials.