Numerical design and scattering losses of a one-dimensional metallo-dielectric multilayer with broadband coupling of propagating waves to plasmon modes in the visible range

摘要

We report on the design, fabrication, and optical characterization of a one-dimensional (1D) metallo-dielectric metamaterial tuned to enhance evanescent wave transmission with kx ≤ 4k0. Taking reflection and transmission measurements from a 1D subwavelength diffraction grating placed on the metamaterial, we show broadbandpropagating wave to surface plasmon coupling in the visible. However, the fabricated device falls short of the design expectations based on coupled-wave numerical simulations. The dips in the reflection spectrum associated with surface plasmon coupling are 40% smaller than predicted, and the transmission exhibits strong depolarization. Overall, the numerical results support that intrinsic metallic losses do not preclude the development of these devices in the visible, but there are considerable plasmon scattering losses from the metamaterial's imperfections. This extrinsic limiting factor needs to be overcome to develop metallo-dielectric metamaterials for practical components for use in superlenses.