Electromagnetic metasurfaces: physics and applications

Abstract

H-shaped resonators (inset) are adopted to realize, respectively, the desired B layer with negative ε and A layers with positive ε at the working frequencies [25]. (d) Top and middle panels: interference model and practical design of the metamaterial antireflection coating. Middle panel: experimentally measured reflectance and transmittance spectra for the normal incidence case. The solid and dashed lines represent the reflectance and transmittance of a bare GaAs surface [26]. (a) Figure 1 reprinted with permission from Martín-Moreno et al.,

Progresses in the practical metasurface for holography and lens

“…However, in the case of a metahologram, which indicates the holography produced by a metasurface, the problems regarding large pixel pitch vanish thanks to its subwavelength periodic length. This is because each meta-atom contains information of the phase or amplitude of light [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20]. In this section, we discuss how light reacts with meta-atoms and review some of the representative metahologram studies together.…”

“…The prefix meta-means to transcend the following suffix, which implies that one can think of the optical metasurface as something that surpasses the normal surface. Metasurfaces are different from normal surfaces because light reacts abnormally at their boundary in an unexpected manner [1][2][3][4][5][6][7][8][9][10][11][12][13]. Practically, they are composed of artificial subwavelength structures that utilize lightmatter interactions for specific purposes.…”

A Thin Self‐Feeding Janus Metasurface for Manipulating Incident Waves and Emitting Radiation Waves Simultaneously

“…To obtain multifunction, there are great deals of literatures about the multifunctional metasurfaces. [ 22–46 ] The metasurfaces in these literatures can be divided into two categories—multifunctional metasurface with ingenious microstructure and tunable multifunctional metasurface. For the first category, the multifunction can be generally obtained in different frequencies or different spaces due to the fascinating and ingenious microstructures.…”

Broadband achromatic metalens in terahertz regime

“…The important aforementioned progress of metalenses was shown to be capable of achromatic imaging by tailoring the phase dispersion of each nanostructure. Most of the studies have focused on meta-devices in the visible or near-infrared region [37,38]. However, investigations of achromatic metalenses using dielectric metasurfaces have seldom been reported in the terahertz regime possessing a high working efficiency.…”