Terahertz beam reconfigurable phase gradient metasurface of VO2 based on different metal–insulator transition temperatures.

In this letter, by using vanadium dioxide (VO2) with metal–insulator transition (MIT) temperatures of 60 ℃ and 72 ℃, respectively, and analyzing the effects of the two states of VO2 before (insulator state) and after (metal state) MIT on the amplitude and phase of the double MIT VO2 (DMITV) unit structure, constituting the terahertz beam reconfigurable phase gradient metasurface of VO2 based on different MIT temperatures, which achieves flexible regulation of terahertz beam. The structure is composed of two different MIT temperature VO2, polytetrafluoroethylene (PTFE) and metal. By changing the external temperature, the structure has different beam deflection angles at different temperatures. At 1.4 THz, when the temperature is below 60 ℃, the beam deflection angle is 0°, when the temperature is between 60 ℃ and 72 ℃, the beam deflection angle is 36° and when the temperature is above 72 ℃, the beam deflection angle is 17°. This terahertz phase gradient metasurface based on VO2 with different MIT temperatures provides a new way to flexibly control terahertz beams, and will have great application prospects in terahertz transmission, imaging, wireless communication, or other fields. [ABSTRACT FROM AUTHOR]