Design of an ultra-wideband switchable terahertz metamaterial absorber using a VO₂ transversally open ring structure

Abstract

This paper proposes a switchable terahertz (THz) metamaterial absorber based on vanadium dioxide (VO2), which can not only realize ultra-wideband (UWB) perfect absorption in the THz range, but also has the ability to adjust the absorption rate by regulating the conductivity of VO2. When VO2 conductivity is 2×105S/m, the designed UWB absorber can achieve over 90% absorption in the frequency range of 2.62–10 THz. Simultaneously, the peak absorption intensity of the absorber can also be regulated dynamically ranging from 100% to 0.8% when the conductivity of VO2 is adjusted to change from 2×105 to 20 S/m. Furthermore, the designed absorber has the advantages of polarization insensitivity and wide-angle absorption. For TE polarization with an incident angle of less than 40° and TM polarization with an incident angle of less than 60°, the absorption rate remains above 90%. The UWB absorber has the advantages of simple structure, wide tuning range, and good absorption performance, and it has potential applications in many fields such as THz filtering, invisibility, sensing, optoelectronic switches, and so on.

Design of an ultra-wideband and switchable VO2-based microwave absorber

“…Therefore, Vanadium dioxide (VO 2 ), a phase change material, suffers a fast response, large modulation depth, and multiple modulation methods [29], as well as a low phase change temperature of 68° [30] is widely used for the design of metamaterial device with the switchable functionalities. However, most of these studies have successfully designed switchable terahertz broadband MA structures [31][32][33][34][35][36][37][38][39][40][41], but very few investigations of switchable MAs using VO 2 for microwave regions have been reported so far [42]. Hence, many efforts have been explored to design a switchable microwave MA structure having both large bandwidth and high absorption performance as recently reported [42,43].…”