Related papers: Broadband gate-tunable THz plasmons in graphene he…
Graphene can support surface plasmons with higher confinement, lower propagation loss, and substantially more tunable response compared to usual metal-based plasmonic structures. Interestingly, plasmons in graphene can strongly couple with…
Graphene has been one of the most investigated materials in the last decade. Its unique optoelectronic properties have indeed raised it to an ideal and revolutionary candidate for the development of entirely novel technologies across the…
We present an extensive study of resonant two-dimensional (2D) plasmon excitations in grating-gated quantum well heterostructures, which enable an electrical control of periodic charge carrier density profile. Our study combines theoretical…
A hybrid metal-graphene metamaterial (MM) is reported to achieve the active control of the broadband plasmon-induced transparency (PIT) in THz region. The unit cell consists of one cut wire (CW), four U-shape resonators (USRs) and monolayer…
Graphene, a single atomic layer of covalently bonded carbon atoms, has been investigated intensively for optoelectronics and represents a promising candidate for high-speed electronics. Here we present a microwave mixer constructed as an…
Graphene supports surface plasmon polaritons with comparatively slow propagation velocities in the THz region, which becomes increasingly interesting for future communication technologies. This ability can be used to realize compact…
Spectacular advances in heterodyne astronomy with both the Herschel Space Observatory and Stratospheric Observatory for Far Infrared Astronomy (SOFIA) have been largely due to breakthroughs in detector technology. In order to exploit the…
Effective control of terahertz radiation requires the development of efficient and fast modulators with a large modulation depth. This challenge is often tackled by using metamaterials, artificial sub-wavelength optical structures…
For future on-chip communication schemes, it is essential to integrate nanoscale materials with an ultrafast optoelectronic functionality into high-frequency circuits. The atomically thin graphene has been widely demonstrated to be suitable…
We demonstrate that the broadband nonlinear optical response of graphene can be resonantly enhanced by more than an order of magnitude through hybridization with a plasmonic metamaterial,while retaining an ultrafast nonlinear response time…
The nonlinear responses of different materials provide useful mechanisms for optical switching, low noise amplification, and harmonic frequency generation. However, the nonlinear processes usually have an extremely weak nature and require…
In this paper we propose and discuss coherent terahertz sources based on charge density wave (plasmon) amplification in two dimensional graphene. The coupling of the plasmons to interband electron-hole transitions in population inverted…
The modulation depth of 2-D electron gas (2DEG) based THz modulators using AlGaAs/GaAs heterostructures with metal gates is inherently limited to < 30%. The metal gate not only attenuates the THz signal (> 90%) but also severely degrades…
We present an asymmetric bifacial graphene metasurface to realize tunable and broadband coherent perfect absorption (CPA) at terahertz (THz) frequencies. The proposed design is composed of two dissimilar graphene square patch metasurfaces…
Graphene is a promising material for nonlinear THz applications owing to its high third-order susceptibility and tunable optical properties. Its strong nonlinear response, driven by free-carrier thermodynamics, facilitates efficient…
The efficient modulation and control of ultrafast signals on-chip is of central importance in terahertz (THz) communications and a promising route toward sub-diffraction limit THz spectroscopy. Two-dimensional (2D) materials may provide a…
Graphene is a unique platform for tunable opto-electronic applications thanks to its linear band dispersion, which allows electrical control of resonant light-matter interactions. Tuning the nonlinear optical response of graphene is…
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…
We present a novel approach to enhance THz nonlinearity by the resonant excitation of two-dimensional plasmons in grating-gate plasmonic crystals. Using a high-electric-field THz pump-THz probe technique, we investigate the nonlinear…
Graphene, owing to its ability to support plasmon polariton waves in the terahertz frequency range, enables the miniaturization of antennas to allow wireless communications among nanosystems. One of the main challenges in the demonstration…