▎ 摘　　要

NOVELTY - The lens has a metal gate layer (1), a medium layer (2) and a graphene microstructure layer (3). The graphene micro-structure layer and the metal gate layer are provided with a bias voltage control device (4) for changing the electrical conductivity of the graphene. The metal grid is a uniform one-dimensional wire grid. The graphene microstructure is a two-dimensional array of x-y planes composed of rectangular units of graphene. The length and width of the rectangular unit of graphene and the angle with the metal grid are changed with the position of the unit. A phase gradient which varies with space is provided to converge polarized light. The focal length is dynamically regulated with the graphene Fermi level, and the focal length is kept constant with the graphene Fermi level by changing order in which units are arranged. The material of medium layer is silicon dioxide. A material of metal gate is polyethylene carbonate (PEC). USE - Focus-adjustable terahertz graphene super-surface lens for imaging system. ADVANTAGE - The double-layer design with metal grid and graphene microstructure ensures high efficiency and transmissive output of orthogonal linear polarized light, and is easy to process. The dynamic change of the focal length of the lens, and large numerical aperture lens are realized. The focus with the graphene Fermi level of moving speed is changed so as to meet the application requirement of different systems. The lens has high numerical aperture, transmission type, high efficiency, and compact structure. DESCRIPTION OF DRAWING(S) - The drawing shows a perspective view of the focus-adjustable terahertz graphene super-surface lens. Metal gate layer (1) Medium layer (2) Graphene microstructure layer (3) Bias voltage control device (4) Incident x-polarized terahertz wave (5)