Multilayer terahertz modulator based on VO2

In this paper, we propose a multi-layer composite structure utilizing metamaterial combined with vanadium dioxide (VO2). Through the excitation of applied voltage, the VO2 located at the gap of the I-shaped structure has the phenomenon of abrupt transition from semiconductor property to metal property, resulting in a change in the resonance state of the first layer structure. When the terahertz wave passes through a two-layer metal structure which have different resonance frequencies, the modulation bandwidth can be expanded. This multi-layer modulator is capable of effective broadband amplitude modulation in 0.168-0.223 THz and 0.348-0.379 THz, which has many potential applications in terahertz wireless communication systems and high-speed imaging systems.