A review of anomalous refractive and reflective metasurfaces

Abstract

Abnormal refraction and reflection refers to the phenomenon in which light does not follow its traditional laws of propagation and instead is subject to refraction and reflection at abnormal angles that satisfy a generalization of Snell’s law. Metasurfaces can realize this phenomenon through appropriate selection of materials and structural design, and they have a wide range of potential applications in the military, communications, scientific, and biomedical fields. This paper summarizes the current state of research on abnormal refractive and reflective metasurfaces and their application scenarios. It discusses types of abnormal refractive and reflective metasurfaces based on their tuning modes (active and passive), their applications in different wavelength bands, and their future development. The technical obstacles that arise with existing metasurface technology are summarized, and prospects for future development and applications of abnormal refractive and reflective metasurfaces are discussed.

A compact frequency-selective absorber with optical transparency

“…In equation (1), where f is the operating frequency, P r and P a represent reactive power and active power, respectively, it can be observed that the bandwidth is positively correlated with active power. As the sheet resistance R increases, the absorption bandwidth becomes wider.…”

“…The artificial electromagnetic metasurface has gained widespread attention and applications due to its low cost and efficient control of electromagnetic wavefronts. The functionalities of electromagnetic metasurfaces include wavefront control with reflection and transmission capabilities, frequency-selective surfaces that modulate amplitude, and electromagnetic perfect absorbers that completely absorb incident waves [1][2][3][4]. A frequencyselective surface (FSS) is a two-dimensional periodically arranged array structure that exhibits different responses to electromagnetic waves of varying frequencies, polarizations, and incident angles.…”

Enhanced terahertz frequency mixing in all-dielectric metamaterial with multiple surface plasmon polaritons resonances

“…Metamaterials, artificially designed structural materials, are utilized to manipulate THz waves by exploiting their exceptional electromagnetic properties. Metamaterials have facilitated the realization of essential functionalities in the THz regime including holograms [4,5], vortex beam generators [6,7], metalenses [8][9][10], and perfect anomalous diffractors [11,12]. Moreover, metamaterials have emerged as a crucial platform for investigating and exploring THz nonlinear phenomena, propelling the field of nonlinear photonics [13].…”

How Thin and Efficient Can a Metasurface Reflector Be? Universal Bounds on Reflection for Any Direction and Polarization

“…[ 23,24 ] Many applications, such as holography, light‐based radars (lidars), virtual/augmented reality, and solar sail steering, also require the ability to reflect power in a specific direction with very high efficiency using thin platforms (e.g., metasurfaces). [ 22,25–31 ]…”

“…[23,24] Many applications, such as holography, light-based radars (lidars), virtual/ augmented reality, and solar sail steering, also require the ability to reflect power in a specific direction with very high efficiency using thin platforms (e.g., metasurfaces). [22,[25][26][27][28][29][30][31] In this paper, we derive an analytical closed-form expression (Equation (10)) for the upper bound on the power reflected, in any direction and polarization, from a generic planar structure of thickness h that is made of a single material characterized by a complex scalar susceptibility χ. No prior assumption about the structural features and details of the optimal design is made, as illustrated in Figure 1.…”