“…Although the individual response of a nanoantenna provides various exciting possibilities, its scattering cross section associated with total scattered power is typically very minimal due to its extremely small size. For this reason, nanoantenna experiments are usually demonstrated with the two-dimensional (2-D) planar array of nanoantennas, representing a type of optical metasurface or metamaterial with custom-designed optical properties for imaging and holography [16][17][18], optical switching [14,19,20], polarization and phase controlling [10,11,21,22], energy harvesting [23][24][25][26][27], and nonlinear optical [14,[28][29][30] applications.…”