A Polarization Insensitive Dual-functional Vanadium Dioxide (VO2)-based Metasurface Structure in the Terahertz Gap

A polarization insensitive dual-functional vanadium dioxide (VO2)-based metasurface structure has been proposed in this communication. It can provide both transmission and absorption of electromagnetic wave at the same frequency band under different thermal excitations. Periodically arranged VO2 square rings have been designed on a silicon dioxide (SiO2) substrate backed by a gold layer comprising periodic square ring slots filled with VO2. The proposed structure offers transparency with 92.69% transmission coefficient at 1 THz under room temperature. The same device works as an absorber with absorptivity around 99.75% at the identical frequency when the temperature reaches to 68°C. It offers angular stability up to 40° for both transmission and absorption performances.