Meta-Chirality: Fundamentals, Construction and Applications

Abstract

Chiral metamaterials represent a special type of artificial structures that cannot be superposed to their mirror images. Due to the lack of mirror symmetry, cross-coupling between electric and magnetic fields exist in chiral mediums and present unique electromagnetic characters of circular dichroism and optical activity, which provide a new opportunity to tune polarization and realize negative refractive index. Chiral metamaterials have attracted great attentions in recent years and have given rise to a series of applications in polarization manipulation, imaging, chemical and biological detection, and nonlinear optics. Here we review the fundamental theory of chiral media and analyze the construction principles of some typical chiral metamaterials. Then, the progress in extrinsic chiral metamaterials, absorbing chiral metamaterials, and reconfigurable chiral metamaterials are summarized. In the last section, future trends in chiral metamaterials and application in nonlinear optics are introduced.

Smart meta-superconductor MgB2 constructed by the dopant phase of luminescent nanocomposite

“…To date, no effective method has been developed to improve the TC of MgB2. The use of metamaterial structures to achieve special properties is an important method developed in recent decades [37][38][39][40][41], and it provides a new approach to improve the TC of superconducting materials.…”

Phase Change Metasurfaces by Continuous or Quasi-Continuous Atoms for Active Optoelectronic Integration

“…As one type of architectural structure with specified mathematical and mechanical form by Robert Hooke in the 1670s, a catenary was first introduced into optics in 2015 by Pu et al [162]. As a quasi-continuous structure, the optical catenary was adopted as one type of special meta-atom to construct a diversity of metasurfaces with high-efficiency phase tailoring [18,166,[175][176][177][178][179].…”

“…In this situation, photonic metasurfaces show more prospects and outperform their volumetric versions mainly due to the ultra-thin and easyto-integrate characteristics. Therefore, a plethora of meta-devices are demonstrated for both amplitude [1] and phase regulation [2], from the visible to terahertz (THz) and microwave range, such as ideal frequency selection [3][4][5], perfect absorption [6][7][8][9], beam steering or deflection [10,11], flat lensing [12,13], vortex beam generation [14][15][16], optical activity [17,18], holography [19][20][21], 3D color holography [22,23] and nonlinear effect [24,25] etc.…”

Angularly stable and broadband chiral metamaterial based design for asymmetric transmission of linearly polarized waves

“…Due to their extreme low-profile, microstrip chiral designs are the leading contenders in PC applications. 6,7 CMMs have been used for cross polarization conversion (CPC) for both linear and circular polarizations. Several types of novel CMM structures have been demonstrated based on three dimensional helices, 8,9 gammadion design, 10 plates pairs, 11 bi-layered cross wires, 12 fractional geometries, 13 and twisted arcs 14 for the polarization manipulation.…”