Tunable broadband terahertz properties in an architecture optimized ITO/VO2 hybrid metamaterial

Abstract

This article proposes an architecture optimized indium-tin-oxide (ITO)/vanadium dioxide (VO2) hybrid metamaterial with optically transparent and tunable broadband terahertz properties. By changing the architecture of subunits, a broadband (∼1 THz) absorption with average absorptivity of 80.0 % has been achieved in an optimized ITO metamaterial at first. With adding strong correlated electron oxide VO2 film, the tunability is introduced in the ITO/VO2 hybrid structures. The most striking finding here is that the position of the VO2 layers in the hybrid structure can efficiently affect both the THz properties and the modulation functionality. In an optimized ITO/VO2 hybrid structure, 84.5 % reflection modulation and 78.9 % absorption modulation within a broadband (0.2 ∼1.0 THz) range are obtained. These findings highlight the architecture optimization for the THz properties in hybrid metamaterials, which is expected to have a great technological impact on the design of optically transparent THz tunable absorbers.