Linear and Circular Dichroism in Graphene-Based Reflectors for Polarization Control
Name:
PhysRevApplied.13.024046.pdf
Size:
2.260Mb
Format:
PDF
Description:
Published version
Type
ArticleAuthors
Amin, M.
Siddiqui, O.
Farhat, Mohamed
Date
2020-02-19Submitted Date
2019-10-18Permanent link to this record
http://hdl.handle.net/10754/661948
Metadata
Show full item recordAbstract
We present an ultrathin graphene metascreen that possesses dispersive optical activity in the early terahertz spectrum. The metascreen design consists of periodically etched L-shaped voids on a graphene substrate backed by a conductive plane. The specific unit-cell design is based on chirality and leads to highly asymmetric radiations from the plasmon-polariton surface currents, leading to linear and circular dichroism. Hence the incident linearly or circularly polarized electric fields are effectively absorbed by the metasurface in different proportions. Consequently, the metasurface assumes half- and quarter-wave-plate behaviors in different parts of the reflected optical spectrum. In particular, we show via full-wave simulations that the dichroic metascreen supports perfect linear-to-circular polarization conversion (circular dichroism) in two adjacent terahertz frequency bands. In two other terahertz bands, it rotates the incoming linearly polarized wave vector by 90° (linear dichroism). Moreover, since graphene has a variable refractive-index dependence on its chemical potential, the dispersion characteristics can be shifted to neighboring frequencies within the early terahertz spectrum. We further demonstrate an angularly stable response for incident angles varying between 0° and 45°. The tunable linear and circular dichroism characteristics are well suited for applications in sensing, imaging, and spectroscopy at terahertz frequencies.Citation
Amin, M., Siddiqui, O., & Farhat, M. (2020). Linear and Circular Dichroism in Graphene-Based Reflectors for Polarization Control. Physical Review Applied, 13(2). doi:10.1103/physrevapplied.13.024046Publisher
American Physical Society (APS)Journal
Physical Review AppliedAdditional Links
https://link.aps.org/doi/10.1103/PhysRevApplied.13.024046ae974a485f413a2113503eed53cd6c53
10.1103/PhysRevApplied.13.024046