Metalens, an important branch of metasurfaces, have shown great capabilities for minimization of traditional optical imaging devices. Various types of metalens have been developed, including achromatic metalens, metalens for spectrum imaging, and bifocus or multifocus lens [72,75,76,77]. As shown in...
They have name variants such as large, intelligent surfaces [136,137], reconfigurable intelligent surfaces [18,138], and software-controlled metasurfaces [139]. Figure 5 shows an RIS-assisted communication system with the RIS reflecting signal, thus enabling communication from the BS to the mobile...