Scattering from a nonlinear metasurface

We present a closed-form analysis of electromagnetic scattering from a nonlinear metasurface. For simplicity, we restrict our attention to the case of an isotropic second-order nonlinear metasurface. We derive the reflectionless conditions for such a nonlinear metasurface, and show that those conditions depend on the direction of wave propagation, which reveals the nonreciprocal nature of the structure. Next, we provide approximate transmitted field expressions obtained by perturbation theory, and we shall present FDTD validations at the conference.