Active and Programmable Metasurfaces with Semiconductor Materials and Devices

Active metasurfaces provide promising tunabilities to artificial meta−atoms with unnatural optical properties and have found important applications in dynamic cloaking, reconfigurable intelligent surfaces, etc. As the development of semiconductor technologies, electrically controlled materials devices become most candidate for programmable due large modulation range, compact footprint, pixel−control capability, small switching time. Here, a technical review active is given terms semiconductors, which consists diodes, transistors, newly rising materials. Physical models, equivalent circuits, recent advances, trends are discussed collectively critically. This represents broad introduction readers just entering this interesting field provides perspective depth those well−established.