Terahertz Wavefront Control Based on Graphene Manipulated Fabry–Pérot Cavities

This letter proposes a new approach for controlling the terahertz wavefront using simply constructed equipment, consisting of graphene-based Fabry-Pérot cavities (GFPCs) arranged regularly in one dimension. The reflection spectrum of each cavity can be efficiently tailored by changing the doping level of the graphene. Specifically, more than 270°, 240°, and 180° of phase shifts are produced near the first, second, and third resonances, respectively. With such a significant degree of freedom for the response phases, we demonstrate three different strategies to organize the array, viz., 4, 3, and 2 GFPC cells-based periodic lattices were designed, respectively, to generate particular propagating directions of the reflection waves. Compared with the metal resonant structures, our scheme is convenient for obtaining the multi-scanning angle and multi-frequency properties. The GFPC structure and the associated arrangement approach are a new addition to the wavefront control toolbox, which is promising for future innovative applications in terahertz sensing, communication, and spectrum splitting.