Related papers: Terahertz metasurface sensor with graphene microst…
In recent years, there has been notable advancement in programmable metasurfaces, primarily attributed to their cost-effectiveness and capacity to manipulate electromagnetic (EM) waves. Nevertheless, a significant limitation of numerous…
Different imaging modalities are used to extract the diverse information carried in an optical field. Two prominent modalities include bright field and phase contrast microscopy that can visualize the amplitude and phase features of a…
Photoelectron emission microscopy PEEM is a powerful tool to spectroscopically image dynamic surface processes at the nanoscale but is traditionally limited to ultra high or moderate vacuum conditions. Here, we develop a novel grapheme…
We designed and implemented a gradient index metasurface for the in-plane focusing of confined terahertz surface waves. We measured the spatial propagation of the surface waves by two-dimensional mapping of the complex electric field using…
We introduce the concept of nonlinear graphene metasurfaces employing the controllable interaction between a graphene layer and a planar metamaterial. Such hybrid metasurfaces support two types of subradiant resonant modes, asymmetric modes…
Metasurfaces are sub-wavelength patterned layers for controlling waves in physical systems. In optics, meta-surfaces are created by materials with different dielectric constants and are capable of unconventional functionalities. We develop…
Metasurfaces can manipulate the amplitude and phase of electromagnetic waves, offering applications ranging from antenna design and cloaking to imaging and communication. Additionally, temporal, and non-linear metasurfaces have the…
The active photonics based on the two-dimensional material graphene has attracted enormous interests for developing the tunable and compact optical devices with high efficiency. Here we integrate graphene into the Fano-resonant…
The paper overviews our recent work on the synthesis of metasurfaces and related concepts and applications. The synthesis is based on generalized sheet transition conditions (GSTCs) with a bianisotropic surface susceptibility tensor model…
High resolution nanoscale imaging in liquid environments is crucial for studying molecular interactions in biological and chemical systems. In particular, electron microscopy is the gold-standard tool for nanoscale imaging, but its…
Graphene has emerged as a promising building block in the modern optics and optoelectronics due to its novel optical and electrical properties. In the mid-infrared and terahertz (THz) regime, graphene behaves like metals and supports…
In 6G wireless communications, functional terahertz reflecting metasurfaces are expected to play increasingly important roles such as beamforming and beamsteering. This paper demonstrates the design of a functional and efficient beamforming…
We provide a mathematical analysis for a metasurface constructed of plasmonic nanoparticles mounted periodically on the surface of a microcapsule. We derive an effective transmission condition, which exhibits resonances depending on the…
The unique terahertz properties of graphene has been identified for novel optoelectronic applications. In a graphene sample with bias voltage added, there is an enhanced absorption in the far infrared region and a diminished absorption in…
In this paper, a broadband tunable polarization converter based on graphene metasurfaces is proposed. This polarization converter works in the terahertz (THz) frequency region, using the advantage of graphene characteristics to have a…
A multiband hybrid metasurface supporting multiple gap-surface plasmon (GSP) and localized surface plasmon (LSP) modes is presented. The structure adopts a metal-dielectric-metal configuration consisting of an aluminum bottom layer, a…
In elastic wave systems, combining the powerful concepts of resonance and spatial grading within structured surface arrays enable resonant metasurfaces to exhibit broadband wave focusing, mode conversion from surface (Rayleigh) waves to…
Using RF signals for wireless sensing has gained increasing attention. However, due to the unwanted multi-path fading in uncontrollable radio environments, the accuracy of RF sensing is limited. Instead of passively adapting to the…
We thoroughly investigate the electromagnetic response of intelligent functional metasurfaces. We study two distinct designs operating at different frequency regimes, namely, a switch-fabric-based design for GHz frequencies and a…
Surface lattice resonances (SLRs) in metasurfaces have become a transformative platform for subwavelength optical devices, leveraging their high quality (Q)-factors, pronounced local field enhancement, and extensive long-range interactions.…