Emergent Functionality and Controllability in Few‐Layer Metasurfaces

Abstract

Recent progress in metamaterial research has successfully exceeded the limitations imposed by conventional materials and optical devices, enabling the manipulation of electromagnetic waves as desired. The distinct characteristics and controlling abilities of metamaterials make them ideal candidates for novel photonics devices not only in traditional optics but also for biological detection, medical science, and metrology. However, the controllability and functionality of both single-layer metasurfaces and bulk metamaterials are not sufficient to meet the requirements of emerging technologies; hence, new solutions must be found. As such technologies advance, new functionalities will emerge as different or identical single-layer metasurfaces are combined. Thus, innovation in few-layer metasurfaces will become an increasingly important line of research. Here, these metasurfaces are classified according to their functionalities and the few-layer metasurfaces that have been proposed up to now are presented in a clear sequence. It is expected that, with further development in this area, few-layer metasurfaces will play an important role in the family of optical materials.

Polarization State Manipulation of Electromagnetic Waves with Metamaterials and Its Applications in Nanophotonics

“…Over the past decade, many eforts have been made in the scientiic community to overcome the drawbacks of complanate metamaterials and improve the polarization state manipulation of electromagnetic waves in nanoscale with new types of metamaterials [25,26]. As one of the solutions, sandwich-like metamaterials constructed with anisotropic resonators, dielectric layer, and highly relective metallic ilm have been proposed to provide an alternate way to realize efective polarization state manipulation in relection mode as shown in Figure 2a and b [27,28].…”

“…One way to solving these problems may be utilizing few-layer metasurfaces [25], the principle of which is illustrated in Figure 11a. The properties of metasurfaces are sum of the individual particles (unit cells), which also means their functionalities are limited by each of the particles.…”

Breaking Malus’ law: Highly efficient, broadband, and angular robust asymmetric light transmitting metasurface

“…In this work, we report on a few‐layer metasurface offering efficient and broadband asymmetric transmission of light. Metasurfaces are sub‐wavelength textured surfaces that can be thought of as the two‐dimensional equivalent of metamaterials . They exhibit versatile, tailored electromagnetic functions such as frequency selectivity , polarization control , wavefront engineering , and even nonlinear responses .…”

A Bilayer Plasmonic Metasurface for Polarization‐Insensitive Bidirectional Perfect Absorption

“…Even though these approaches can realize the bidirectional perfect absorption of optical waves, the heavy dependence of absorption efficiency on the phase difference between the two coherent beams extremely limits the applications of metasurfaces‐based bidirectional perfect absorbers. Recent advances in few‐layer metasurfaces show some advantages to meet this challenge . By involving a large phase gradient along the metasurface interface, Li et al.…”