Tunable circular conversion dichroism of single-layer twisted graphene-patterned metasurface.
iScience
; 26(3): 106115, 2023 Mar 17.
Article
in En
| MEDLINE
| ID: mdl-36852279
Two-dimensional (2D) chirality-induced asymmetric transmission/reflection has great potential for polarization applications. Usually, asymmetric effects resulting from circular conversion dichroism (CCD) occur in chiral metasurfaces. Here, we propose a single-layer twisted graphene-patterned (with tilted elliptical hole arrays) metasurface and theoretically reveal its tunable CCD in the terahertz (THz) region. The unit cell of the metasurface is achiral. Merely by altering the in-plane orientation of holes for structural 2D chirality, a tunable CCD can be achieved at normal incidence. Interestingly, the reflection phase can be considered an intuitive method to show this metasurface's anisotropy, which complements the conventional CCD measurement in characterizing chiral materials. Furthermore, we can achieve active CCD based on the tunability of graphene. Due to the Fabry-Pérot resonance, a multiband enhancement of CCD spectrum will happen by changing the dielectric layer thickness. The proposed metasurface provides more flexible opportunities for designing active THz devices for polarization manipulation.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Language:
En
Journal:
IScience
Year:
2023
Document type:
Article
Affiliation country:
China
Country of publication:
United States