Role of loss in all-dielectric metasurfaces.

Arrays of dielectric cylinders support two fundamental dipole active eigenmodes, which can be manipulated to elicit a variety of electromagnetic responses in all-dielectric metamaterials. Dissipation is a critical parameter in determining functionality; the present work varies material loss to explore the rich electromagnetic response of this class of metasurface. Four experimental cases are investigated which span electromagnetic response ranging from Huygens surfaces with transmissivity T = 94%, and phase ϕS₂₁ = 235°, to metasurfaces which absorb 99.96% of incident energy. We find perfect absorption to be analogous to the driven damped harmonic oscillator, with critical damping occurring at resonance. With high phase contrast, transmission, and absorption all accessible from a single system, we present a uniquely diverse all-dielectric system.