Nonlinear photonic metasurfaces

In linear optical regime, many novel optical functions have been demonstrated by using ultrathin photonic metasurfaces. The main concept of metasurface is to appropriately assembly the spatially variant meta-atoms on a subwavelength scale, and realize the manipulations of polarization, phase and amplitude of light. Recently, the nonlinear optical properties of photonic metasurfaces have attracted a lot of attention. In this review, we discuss the design, material selection, symmetry consideration of the meta-atoms, as well as the applications such as nonlinear chiral optics, nonlinear geometric Berry phase and nonlinear wavefront engineering. Lastly, we point out the challenges and potentials of nonlinear photonic metasurfaces for manipulating the light-matter interactions.