Fig. 1

Schematic view of SHG induced by hybrid metasurface with a wall ring and paired bull-eye rings. The left corner inset shows a unit cell of the metasurface with geometrical parameters of \({r}_{1}\) = 124 nm, \({r}_{0}\) = 105 nm, \({r}_{2}\) = 40 nm, \({r}_{3}\) = 20 nm, \({r}_{4}\) = 55 nm, \(h\) = 80 nm, \({c}_{0}\) = 10 nm, \({c}_{1}\) = 20 nm