Ultra-thin and high-efficiency graphene metasurface for tunable terahertz wave manipulation

Abstract

We propose a type of ultra-thin metasurfaces composed of rectangular graphene patches supporting orthogonal plasmonic resonances, which can work in transmission or reflection modes for dynamic terahertz wavefront manipulation with high polarization conversion ratio. By controlling the response of each patch via electrical biasing, the phase of the output wave can be tuned in a wide range over 180° while keeping its amplitude high and relatively stable. We demonstrate several functional devices based on such metasurfaces: a linear polarization converter with nearly 100% polarization conversion ratio, a switchable anomalous wave deflection device, and a dual-polarity focusing mirror with the focal spot tunable in both the transversal and longitudinal directions.

Terahertz linear to circular polarization converter based on reflective metasurface

“…Despite having the lower thickness, they have acceptable optical responses in comparison with conventional metamaterials, and therefore they are a good replacement for bulky metamaterials [1,3,4,5]. Nowadays, metasurfaces are so attractive because of their applications in sensors [6], imaging devices [7], absorption devices [8], and beam manipulation devices [9], such as holograms, cloaking devices, and polarization converters in the microwave, terahertz (THz), and optical regimes. Due to the small volume, low absorption, and tunable optical responses of metasurfaces, they have been extensively used to linear to circular polarization converters (LTC-PC) [10,11].…”

Tunable Circular Polarization Detection and Full Stokes Measurement Structure

“…Content may change prior to final publication. Citation information: DOI 10.1109/JPHOT.2021.3075692, IEEE Photonics Journal adjusted [14]- [15]. Therefore, more polarization information in the spectral dimensions can be obtained.…”

Switchable Polarization Selective Terahertz Wavefront Manipulation in a Graphene Metasurface

“…The optical property of graphene is characterized by surface conductivity, which can be tuned by changing its Fermi energy via chemical doping and gate voltage [12]- [14]. Graphene based metaface can also be designed to manipulate wave in THz frequency region [15]- [17]. Recently, graphene ribbons are introduced to metasurface to design cylindrical lens [18], [19], in which only one polarization incidence is considered, and the switchable characteristic of graphene has not been fully investigated.…”