Wide-angle Reconfigurable Refraction by Silicon Fourier Metasurfaces

Abstract

Abstract We design metasurfaces based on silicon films with smooth relief described by several Fourier harmonics and study their ability to redirect the refracted light over a wide angular range controlled by subtle variations of the optical setup. We use semi-analytical approach based on the Rayleigh hypothesis as well as full-scale numerical solutions to optimize the relief shape. To illustrate the reconfigurability potential, we design metasurfaces efficiently redirecting the refracted light from 83° to −73° with respect to the normal, when the angle of incidence is varied from 0° to 2°, and from 80° to −74°, when the substrate permittivity is altered from 2.3 to 2.2.