A5101534703- Plasmonic and Surface Plasmon Research
- Thermal Radiation and Cooling Technologies
- Terahertz technology and applications
- Gyrotron and Vacuum Electronics Research
- Photonic and Optical Devices
- Metamaterials and Metasurfaces Applications
- Microwave Engineering and Waveguides
- Superconducting and THz Device Technology
- Optical Coatings and Gratings
- Near-Field Optical Microscopy
- Photonic Crystals and Applications
- Gold and Silver Nanoparticles Synthesis and Applications
- Pulsed Power Technology Applications
- Graphene research and applications
- 2D Materials and Applications
- MXene and MAX Phase Materials
- Insects and Parasite Interactions
- Advanced Fiber Laser Technologies
- Millimeter-Wave Propagation and Modeling
- Optical Systems and Laser Technology
- Advanced SAR Imaging Techniques
- Advanced Thermoelectric Materials and Devices
- Complex Network Analysis Techniques
- Microwave Imaging and Scattering Analysis
- Antenna Design and Analysis
Shenzhen Institutes of Advanced Technology
2024
University of Electronic Science and Technology of China
2015-2024
Chengdu Institute of Information Technology (China)
2024
Ministry of Education of the People's Republic of China
2018-2023
National University of Defense Technology
2022
Henan University of Economic and Law
2020
Communication University of China
2014
University of Wollongong
2014
Although surface plasmon polaritons (SPPs) resonance in graphene can be tuned the terahertz regime, transforming such SPPs into coherent radiation has not been achieved. Here, we propose a graphene-based source with greatly enhanced intensity. The works at room temperature, it is tunable and cover whole regime. intensity generated this method 400 times stronger than that from conventional dielectric or semiconducting comparable to most advanced photonics as quantum cascade laser. physical...
We demonstrate a mechanism of efficiently transforming surface plasmon polaritons (SPPs) into Cherenkov terahertz (THz) radiation. In structure where multilayer graphene is deposited on dielectric substrate with buffer layer, the energy SPPs can be significantly enhanced. The dispersion crosses light line if layer has low permittivity relative to substrate. As result, readily transformed radiation without need wavevector compensation. Compared from structures graphene, power density enhanced...
Abstract Terahertz (THz) radiation can revolutionize modern science and technology. To this date, it remains big challenges to develop intense, coherent tunable THz sources that cover the whole frequency region either by means of only electronics (both vacuum semiconductor electronics) or photonics (lasers, for example, quantum cascade laser). Here we present a mechanism which overcome these difficulties in generation. Due natural periodicity 2π both circular cylindrical graphene structure...
We demonstrate a concept that allows direct excitation of surface plasmon polaritons (SPPs) by moving electron bunch above single layer graphene sheet deposited on dielectric substrate without any additional coupling requirements. show if the two-dimensional current in is dominated third order nonlinear effect when electric field exceeds moderate strength ∼5 kV/cm, SPP mode can cross light line although group velocity remains much smaller than speed light. This gives rise to transformation...
We demonstrate optical bistability in a prism-air-graphene-dielectric structure. Under moderate electric field the terahertz frequency regime, third order nonlinear conductivity is comparable to linear conductivity. The enhances energy of surface plasmon polaritons. Both and polaritons depend on strength current graphene layer. When considering excitation Kretschmann configuration, reflectance as function exhibits bistability. origin dependence mode. have determined parameter regime for...
In this paper, a theoretical investigation on plasmon modes in circular cylindrical double-layer graphene structure is presented. Due to the interlayer electromagnetic interaction, there exist two branches of modes, optical mode and acoustic mode. The characteristics these such as pattern, effective index propagation loss, are analyzed. modal behaviors can be effectively tuned by changing distance between layers, chemical potential permittivity dielectric. Importantly, breakup tradeoff...
Unintercalated MXenes have advantages in energy saving, cost, yield and stability compared to monolayer MXenes. An all-MXene based block type TE device with undelaminated was fabricated used wearable heat harvesting.
A 500 GHz TE <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">85</sub> mode continuously frequency-tunable gyrotron has been designed, fabricated and investigated experimentally. In the experiment, operates at second cyclotron harmonic stably. The operating frequency is tuned by means of adjusting magnetic field or beam energy. variation output power also investigated. It found that when changed, frequency-tuning range much bigger than energy changed.
Transition radiation (TR) induced by electron–matter interaction usually demands vast accelerating voltages, and the angle cannot be controlled. Here we present a mechanism of direction controllable inverse transition (DCITR) in graphene-dielectric stack excited low-velocity electrons. The revealed shows that hyperbolic-like spatial dispersion superposition individual bulk graphene plasmons (GPs) modes make fields, which are supposed to confined on surface, radiate along special normal...
A frequency-tunable gyrotron with multiband radiation has been designed, manufactured, and investigated experimentally. The frequency tuning scheme utilizing transverse modes switching axial mode transition is employed to obtain radiation. Three TE02, TE43, TE24 are excited successively the increase of magnetic field. main operating these 140, 250, 263 GHz, respectively. Experimental results indicate that a certain frequency-tuning range can be obtained at each band by means exciting series...
As a terahertz (THz) radiation source, the frequency-tunable gyrotron is promising in application and attractive to researchers. In this article, nonstationary phenomenon operating different regimes—gyromonotron, transition, gyro-backward-wave oscillator (BWO)—has been investigated detail by 3-D particle cell (PIC) simulation. Simulated results demonstrate that among three regimes, gyromonotron has strongest capability keep stationary, oscillations are most likely occur transition regime....
In this paper, the enhanced terahertz radiation transformed from surface plasmon polaritons, excited by a uniformly moving electron bunch, in structure consisting of monolayer graphene supported on dielectric grating with arbitrary profile is investigated. The results show that has significant influence dispersion curves and characteristics including frequency intensity. dependence shape for both symmetric asymmetric gratings studied detail. Moreover, we find that, an certain profile, there...
We demonstrate a physical mechanism for terahertz (THz) generation from surface plasmon polaritons (SPPs). In structure with bulk Dirac semimetals (BDSs) film deposited on dielectric substrate, the energy of asymmetric SPP mode can be significantly enhanced to cross light line substrate due SPP-coupling between interfaces film. Therefore, SPPs immediately transformed into Cherenkov radiation without removing wavevector mismatch. Additionally, symmetric also dramatically lifted when buffer...
Approaches to generate and manipulate Cherenkov radiation (CR) are challenging yet meaningful. Optical topological transition (OTT) in novel materials metamaterials is also promising for modern photonics. We study the OTT of CR graphene-based hyperbolic (GHMs) first time. In GHMs, conventional can be switched when crossing frequency. This frequency altered by metamaterial components external optical elements. For instance, ultrafast pumps cause an from elliptical state. Then, excited...
The mediated coupling of surface plasmon polaritons (SPPs) by a parallel moving electron beam is demonstrated in this paper. theoretical analysis shows that the excited spoof (SSPs) on grating placed above metal films play role as excitation source coupling. numerical calculations and particle-in-cell simulations demonstrate significant advantages SSPs mediately coupled SPPs contrast with directly. photo density reaches up to 106 per cm2 for charge 100 nC/cm, which two orders magnitude...
In this article, the experimental investigations on a 263-GHz gyrotron are presented. With change of operating magnetic field and beam energy, frequency is adjusted output power also varied. It found that when changes from 9.59 to 9.82 T at fixed voltage 20 kV current 0.8 A, increases 263.39 264.84 GHz, frequency-tuning range about 1.45 26 463 W. When 14.4 22.2 9.65 T, decreases 263.68 263.40 0.28 52 424 kV, but 120 880 mA, 21 277 W, 263.396 263.425 frequency-tunable 0.029 GHz. The effects...
In this Letter, the enhanced and directional radiation in a wide terahertz (THz) frequency range graphene hyperbolic medium excited by an electric dipole is presented. The numerical simulations theoretical analyses indicate that comes from strong surface plasmon couplings medium, consisting of alternative dielectric substrate layers. simulation results also show peak power flow THz dramatically more than 1 order magnitude over general within certain distance dipole, electromagnetic fields...
Nowadays, research on social networks has attracted a large amount of attention from both academic and industrial societies. To understand the diffusion process guide viral marketing, it is importance to model then estimate influence seed user target user, which defined as in this paper. In famous models like independent cascade linear threshold model, tremendous computational costs are usually required estimating probability through simulation. paper, we adopt duplicate forwarding propose...
We demonstrate a physical mechanism of multicolor coherent terahertz (THz) Smith–Purcell radiation from surface plasmon polaritons (SPPs). In Dirac semimetals gratings with very deep and narrow slits, two types SPP modes, the cavity ordinary can be excited by fast electrons under different excitation conditions then diffracted into in specific directions. The intensity is remarkably enhanced when SPPs are excited, frequencies widely tuned adjusting parameters grating electrons. Our findings...
Abstract In terahertz vacuum electronic devices, sheet beam can improve the interaction efficiency effectively. A rectangular cavity extended oscillator driven by in band is studied this article. Specially, interact with higher mode structure such as TM 31 mode. This will have advantage of being able to operate at a frequency than fundamental 0.1 THz (EIO) designed based on dispersion characteristics, S parameters and particle‐in‐cell simulation calculation. The results show that voltage 12...