High-efficiency full-phase modulation of a terahertz wave based on a dielectric metasurface

In this paper, we propose a transmissive terahertz metasurface, consisting of periodically arranged subwavelength silicon cross resonators. Based on the theory of electromagnetic dipole resonance, and changing the structural parameters and directions of cross resonators; the phase modulation of a terahertz wave can be realized at a target terahertz frequency. By employing full-wave finite element numerical simulation, we utilize the metasurface to achieve an almost full phase 2π control in the terahertz band, and the transmission efficiency is over 90%. The proposed transmissive metasurface has potential applications in some terahertz functional devices, such as lenses, wave plates and optical vortex converters. (letter)