Reconfigurable Mode Vortex Beam Generation Based on Metasurface Using VO2 at Different Metal-Insulator Transition Temperatures

In this letter, by using vanadium dioxide (VO
2
) with metal-insulator transition (MIT) temperatures of 60°C and 72°C respectively, and analyzing the effects of the two states of VO
2
before (insulator state) and after (metal state) MIT on the amplitude and phase of the double MIT VO
2
(DMITV) unit structure, constituting the orbital angular momentum (OAM) beam mode reconfigurable metasurface of VO
2
based on different MIT temperatures, which achieves flexible regulation of OAM beam. By changing the external temperature, the structure can generate different modes of OAM beam at different temperatures. The results show that at 14 GHz, the metasurface designed in this paper is relative to a reflecting surface when the temperature is lower than 60°C, when the temperature is between 60°C and 72°C, OAM beam with mode $l=1$ can be generated, when the temperature is above 72°C, the OAM beam with mode $l=2$ can be generated, which expected to be applied to wireless communication.