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Handbook of Graphene || Modelling of Graphene Nanoribbons Antenna Based on MoM‐GEC Method to Enhance Nanocommunications in Terahertz Range
摘要： In this chapter, we present an electromagnetic modelling formulation of graphene nanoribbon antenna based on moments method combined to the generalized equivalent circuit method (MoM-GEC). The electrical properties of graphene are introduced in the mathematical formulation via a quantum mechanical conductivity deduced from the Kubo formalism. The antenna structure is shielded in a rectangular waveguide with electric boundary walls. Next, the global antenna structure is modelled by an electric equivalent circuit to investigate the antenna parameters. It is proved that, graphene nanoribbon-based antenna presents similar performances as well as conventional one, hence allowing to work at terahertz frequencies range. The high input impedance of a single graphene nanoribbon antenna causes an impedance mismatch problem, which requires the use of an antenna array. So, the coupling phenomena have been well studied in order to optimize the antenna response. Obtained numerical results show that the antenna resonant frequency is very sensitive to the variation of the graphene chemical potential. This leads to a reconfigurable antenna by a simple control of bias voltage. On the other hand, it is showed that, at terahertz frequencies, graphene nanoribbon antenna array allows to enhance the far field communication for short distances, which is beneficial for nanocommunications.
关键词： antenna array,nanocommunications,dynamic conductivity,terahertz range,nanoantenna,MoM-GEC method,Graphene nanoribbon
更新于2025-09-11 14:15:04
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[IEEE 2018 IEEE International Conference on Computational Electromagnetics (ICCEM) - Chengdu (2018.3.26-2018.3.28)] 2018 IEEE International Conference on Computational Electromagnetics (ICCEM) - Control Enhancement of Dipole Emission Using Hybrid Metal-Dielectric Nanoantenna
摘要： A novel hybrid nanoantenna comprising a stack of two cylinders is proposed to control the enhancement of the dipole emission. The bottom cylinder is made of plasmonic metal to generate large field enhancement to boost the excitation rate of the dipole. The top cylinder is made of high permittivity low loss dielectric to enhance the far field emission intensity of the dipole while maintaining high quantum efficiency. The design principle revealed here can be extended to other geometries and is beneficial to the research fields such as fluorescence enhancement, Raman spectroscopy, and single photon source, among others.
关键词： Nanoantenna,dipole radiation,Hybrid,low loss,enhancement
更新于2025-09-09 09:28:46
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Coherent surface plasmon amplification through the dissipative instability of 2D direct current
摘要： We propose an original concept for on-chip excitation and amplification of surface plasmon polaritons. Our approach, named nanoresotron, utilizes the collective effect of dissipative instability of a 2D direct current flowing in vicinity of a metal surface. The instability arises through the excitation of self-consistent plasma oscillations and results in the creation of a pair of collective surface electromagnetic modes in addition to conventional plasmon resonances. We derive the dispersion equations for these modes using self-consistent solutions of Maxwell’s and 2D hydrodynamics equations. We find that the phase velocities of these new collective modes are close to the drift velocity of 2D electrons. We demonstrate that the slow mode is amplified while the fast mode exhibits absorption. Estimates indicate that very high gain are attainable, which makes the nanoresotron a promising scheme to electrically excite and regenerate surface plasmon polaritons.
关键词： dissipative instability of DC current,electrical excitation of nanoantenna,self-consistent 2D plasma oscillation
更新于2025-09-09 09:28:46
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[IEEE 2018 Photonics North (PN) - Montreal, QC, Canada (2018.6.5-2018.6.7)] 2018 Photonics North (PN) - Double Hot-Spot Dual-Polarization Chand-Bali Nanoantenna for NIR Detection Applications
摘要： In this work, we introduce a novel design of a gold nanoantenna array. The nanoantenna consists of two elliptical patches. A vertical oval coincides with the minor axis of the horizontal oval. An elliptical aperture etched out from the horizontal one resulting in our Chand-Bali shaped nanoantenna. The geometrical dimensions are properly selected such that two symmetrical small gaps are created. The electric field intensity has a significant enhancement in these two gaps at the same resonance frequency within the near-infrared (NIR) regime for both orthogonal polarizations. The new design offers an improved performance for IR detection and harvesting applications.
关键词： energy harvesting,nanoantenna,NIR,dual polarization,electric field enhancement
更新于2025-09-04 15:30:14
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Dewetting mechanisms and their exploitation for the large-scale fabrication of advanced nanophotonic systems
摘要： Recent progress in submicron- and nano-fabrication technologies has led to the emergence of novel photonic structures such as optical nanoantennas and metasurfaces. Real-life applications of these advanced photonic structures still require substantial improvement of the fabrication processes, in terms of their throughput and cost-effectiveness. Because of its simplicity and effectiveness, dewetting of a thin film has attained increasing attention as a feasible process for improving the scalability and productivity. Here, we provide an overview of the mechanisms and phenomenologies of dewetting to foster an improved fundamental understanding necessary for the optimisation of the dewetting process condition and template design. We then review the strategies demonstrating the use of templated-dewetting for producing well-aligned arrays of submicron- and nanostructures with great control over their size, shape and arrangement. Recent applications of dewetted structures in advanced nanophotonics are reviewed with an emphasis on the exploitation of dewetting mechanisms. Special attention is given to the fabrication of resonant optical nanoantennas and nanophotonic applications in which high repeatability and throughput are important parameters: sensing, colourisation, photovoltaics and nonlinear light frequency conversion. We expect this review to provide a basis for the use of thin-film dewetting to realise the industrial-level fabrication of various practical advanced photonic systems.
关键词： optical nanoantenna,interfacial instability,plasmonics,all-dielectric nanophotonics,nanofabrication,advanced photonic applications,Dewetting,thin film
更新于2025-09-04 15:30:14
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Near-Field and Far-Field Thermal Emission of an Individual Patch Nanoantenna
摘要： The far-field spectral and near-field spatial responses of an individual metal-insulator-metal nanoantenna are reported, using thermal fluctuations as an internal source of the electromagnetic field. The far-field spectra, obtained by combining Fourier transform infrared spectroscopy with spatial modulation based on a light falloff effect in a confocal geometry, have revealed two distinct emission peaks attributed to the excitation of the fundamental mode of the nanoantenna at two distinct wavelengths. Superresolved near-field images of the thermally excited mode have been obtained by thermal radiation scanning tunneling microscopy. Experimental results are supported by numerical simulations showing that it is possible to excite the same mode at different wavelengths near a resonance of the insulating dielectric material forming the antenna.
关键词： near-field,nanoantenna,thermal emission,microscopy,spectroscopy,far-field
更新于2025-09-04 15:30:14