Flexible manipulation terahertz beam based on an all-dielectric metasurface by utilizing addition and convolution algorithms.

The flexibly manipulated terahertz wave is currently a hot research topic. To address this challenge, we proposed an all-dielectric coding metasurface for shaping the terahertz wave including beam splitting, beam deflection, vortex beam generators, and a vortex beam and multi-beam splitting combination by combining addition with the convolution theorem. This work represents what we believe to be a new method of combining terahertz wave regulation with digital signal processing and opens up the versatile design ideas of multifunctional metadevices.

Frequency regulated transmission-reflection integration modes of a terahertz metasurface.

The conventional transmission and reflection operating mode switching metasurface depends on phase change materials, which are often difficult to integrate with metasurface devices and work in real time. Here, we propose an integration of a transmission-reflection metasurface that can dynamically control beam direction and functions in both transmission and reflection modes by varying the frequency of the incident wave. Remarkably, the transmission and reflection modes of terahertz beam manipulation can be obtained by illuminating only the transmission side of the metasurface. The full-wave simulation results are in good agreement with the theoretically calculated results, which verifies the terahertz wave manipulation capability of the proposed structure. This metasurface provides a design method for full-space terahertz beam regulation devices.