Related papers: Dynamic Terahertz Beam Steering Based on Graphene …
The extraordinary electronic properties of graphene, such as its continuously gate-variable ambipolar field effect and the resulting steep change in resistivity, provided the main thrusts for the rapid advance of graphene electronics. The…
As the terahertz (THz) band emerges as a pivotal technology for next-generation wireless communications, accurate channel modeling in dynamic environments becomes increasingly critical, particularly for scenarios involving reflective…
Active metasurfaces promise spatiotemporal control over optical wavefronts, but achieving high-speed modulation with pixel-level control has remained an unmet challenge. While local phase control can be achieved with nanoscale optical…
Active metasurfaces, which are arrays of actively tunable resonant elements, can dynamically control the wavefront of the scattered light at a subwavelength scale. To date, most active metasurfaces that enable dynamic wavefront shaping…
Known coherent metasurfaces control interference of waves of a given frequency with other coherent waves at the same frequency, either illuminating from a different direction or created as intermodulation products. In this paper, we…
Terahertz (THz) radiation is a powerful tool with widespread applications ranging from imaging, sensing, and broadband communications to spectroscopy and nonlinear control of materials. Future progress in THz technology depends on the…
This is a brief overview of the main physical ideas for application of field effect transistors for generation and detection of TeraHertz radiation. Resonant frequencies of the two-dimensional plasma oscillations in FETs increase with the…
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…
We report a highly efficient tunable THz reflector in graphene. By applying a small gate voltage (up to 3 V), the reflectance of graphene is modulated from a minimum of 0.79% to a maximum of 33.4% using graphene/ionic liquid structures at…
Metasurfaces consisting of electrically thin and densely packed planar arrays of subwavelength elements enable an unprecedented control of the impinging electromagnetic fields. Spatially modulated metasurfaces can efficiently tailor the…
We demonstrate that phase-difference between terahertz signals on the source and drain of a field effect transistor (a TeraFET) induces a plasmon-assisted dc current, which is dramatically enhanced in vicinity of plasmonic resonances. We…
Metasurfaces in metal/insulator/metal configuration have recently been widely used in photonics research, with applications ranging from perfect absorption to phase modulation, but why and when such structures can realize what kind of…
We present a metamaterial-based terahertz (THz) sensor for thickness measurements of subwavelength-thin materials and refractometry of liquids and liquid mixtures. The sensor operates in reflection geometry and exploits the frequency shift…
We demonstrate terahertz (THz) imaging and spectroscopy of a 15x15-mm^2 single-layer graphene film on Si using broadband THz pulses. The THz images clearly map out the THz carrier dynamics of the graphene-on-Si sample, allowing us to…
We have designed and fabricated a new type of terahertz (THz) emitter that radiates THz waves along the surface-normal direction because of the lateral distributions of the transient electric dipoles. The excitation and measurements were…
Exploration of optical non-linear response of graphene predominantly relies on ultra-short time domain measurements. Here we propose an alternate technique that uses frequency modulated continuous wavefront optical fields, thereby probing…
The terahertz spectral regime, ranging from about 0.1 to 15 THz, is one of the least explored yet most technologically transformative spectral regions. One current challenge is to develop efficient and compact terahertz emitters/detectors…
Ultrafast manipulation of optical resonance can establish the time-boundary effect in time-variant media leading to a new degree of freedom for coherent control of electromagnetic waves. Here, we demonstrate that a free-standing all…
In this work, we theoretically and experimentally study the conversion from a circularly polarized plane electromagnetic wave into a linearly polarized transmitted one using anisotropic self-complementary metasurfaces. For this purpose, a…
We present experimental and numerical studies of localized terahertz surface waves on a subwavelength-thick metamaterial film consisting of in-plane split-ring resonators. A simple and intuitive model is derived that describes the…