Analog Computing Using Reflective Plasmonic Metasurfaces

Motivated by the recent renewed interest in compact analog computing using light and metasurfaces (Silva, A. et al. Science 2014, 343, 160-163), we suggest a practical approach to its realization that involves reflective metasurfaces consisting of arrayed gold nanobricks atop a subwavelength-thin dielectric spacer and optically thick gold film, a configuration that supports gap-surface plasmon resonances. Using well-established numerical routines, we demonstrate that these metasurfaces enable independent control of the light phase and amplitude, and design differentiator and integrator metasurfaces featuring realistic system parameters. Proof-of-principle experiments are reported along with the successful realization of a high-quality poor-mans integrator metasurface operating at the wavelength of 800 nm.