Design of a Terahertz Full-Adder Based on VO2-Integrated Cascaded Metasurfaces

A terahertz (THz) logic device for realizing terahertz full-adder operation is proposed. It is based on electrically controlled vanadium dioxide (VO2)-integrated cascaded metasurfaces. This terahertz full-adder consists of cascaded metasurfaces embedded with VO2 films , terahertz reflectors and terahertz beam splitters. Owing to the insulator-to-metal phase transition (IMT) characteristics of VO2, the hybrid metasurfaces can work as photon switches to change the transmittance of terahertz waves and achieve high amplitude modulations and logic gate operations. Finite Element Method (FEM) simulation results numerically verify the proposed data selector operations. Each metasurface switch has an contrast ratio greater than 15dB at the working frequency. This kind of electrically controlled VO2-based hybrid metasurfaces full-adder potentially promotes the design and implementation of multifunctional electron-photon devices in future THz computing and communication.

I. Introduction

Terahertz wave is electromagnetic wave falling in the far-infrared band within the frequency ranging from 0.1 to 10 THz as a bridge between the millimeter and light waves in the electromagnetic spectrum [1],[2]. THz band is the new frontier of communications technology [3],[4]. With the development of information technology, the increasing of the bandwidth and bit rate almost reaches the bottleneck and the electronic circuits cannot meet the growing demand for practical applications [5]. The transition from electronics to optics and photonics is necessary [6].