Dual-mode terahertz wave beam modulator based on medium metasurface, method and application

The invention provides a dual-mode terahertz wave beam modulator based on a medium metasurface, a method and an application. The device comprises a plurality of metamaterial units arranged according to a certain rule, each metamaterial unit sequentially comprises a bottom VO2 layer, a dielectric isolation layer and a top VO2 layer from bottom to top, and centers of the bottom VO2 layer, the dielectric isolation layer and the top VO2 layer are superposed. The device is completely made of a dielectric material and does not contain a metal material, and the device can realize dynamic switching between a transmission mode and a reflection mode through thermal control or light control. In the reflection mode, the device efficiently reflects and splits terahertz waves, which is equivalent to a reflection type beam splitter. In the transmission mode, the device efficiently transmits the terahertz waves. Compared with other reflection type beam splitters, by using the device of the invention,when the device does not