Anomalous behavior of nearly-entire visible band manipulated with degenerated image dipole array

Abstract

Recently, the control of anomalous light bending via flat gradient-phase metasurfaces has enabled many unprecedented applications. However, either low manipulation efficiency or challenging difficulties in fabrication hinders their practical applications, in particular in the visible range. Therefore, a concept of degenerated image dipole array is reported to realize anomalous light bending with high efficiency. A continuous phase delay varying rather than a discrete one, along with an in-plane wave vector is utilized to achieve anomalous light bending, by controlling and manipulating the mutual coupling between dipole array and the dipole array of its image. The anomalous light bending covers almost the entire visible range with broad incident angles, accompanied with preserved well-defined planar wavefront. In addition, this design is feasible to be fabricated with recent nanofabrication techniques due to its planarized surface configuration. The concept of imperfect image dipole array degenerated from ideal metamaterial absorbers surprisingly empowers significant enhancement in light manipulation efficiency for visible light in a distinct fashion.

Advances in Full Control of Electromagnetic Waves with Metasurfaces

“…[ 52 ] It was also used to demonstrate anomalous light propagation covering almost the entire visible band with efficiency beyond the theoretical limit of single non-magnetic metasurfaces. [ 53 ] …”

Broadband asymmetric light transmission through tapered metallic gratings at visible frequencies

“…Recently, theoretical and experimental studies have proven that chiral metamaterials242526272829, hyperbolic metamaterials30 and all-dielectric digital metasurfaces3132 can enable asymmetric transmission for circularly and linearly polarized light2933. By judiciously engineering parameters of individual building blocks, such as geometry, size and material, metasurfaces are promising to replace conventional electromagnetic elements in nanophotonic devices3435. However, to the best of our knowledge, few works were concerned with the broadband asymmetric transmission (BAT) in the visible frequency range, and most of the proposed diode-like devices with asymmetric transmission were designed to operate either in a narrow band30 or beyond the visible spectrum range36.…”

Metasurfaces-Based Absorption and Reflection Control: Perfect Absorbers and Reflectors

“…This produces an additional effective wave vector to the reflected photons; thus different wavelengths of light are reflected at different angles, giving a rainbow anomalous reflection [87,88]. This design exhibits high broadband reflectivity with an average of over 86% between 450 and 800 nm.…”