- 标题
- 摘要
- 关键词
- 实验方案
- 产品
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Graphene Photonics || Plasmonics
摘要： Graphene has unique plasmonic properties because of its unusual electromagnetic properties and its 2D geometric structure. Graphene supports plasma oscillations when it has a nonzero chemical potential. Different from a metal, which has a fixed carrier density, thus a fixed plasma frequency, graphene is similar to a semiconductor in that its carrier density, thus its plasma frequency, can be varied by varying its chemical potential through, for example, impurity doping, electrical modulation, or optical illumination. Nevertheless, graphene is very different from an ordinary semiconductor because of its unique band structure and its 2D geometry. As a 2D material, graphene naturally supports true surface plasmons and, in a certain spectral region depending on its chemical potential, surface plasmon polaritons. As discussed in preceding chapters, the electromagnetic properties of graphene approach those of a conductor at low frequencies and those of a dielectric at optical frequencies. Between the two limits, particularly in the terahertz frequency region, graphene has sophisticated electromagnetic properties that can be tuned through varying its chemical potential. For this reason, graphene has very interesting plasmonic properties that lead to many useful applications in the terahertz region.
关键词： Surface Plasmons,Plasmonics,Graphene,Surface Plasmon Polaritons,Terahertz
更新于2025-09-16 10:30:52
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Ultrafast Nano-scale Optical Switching in a Plasmonic Interferometer with Enhanced Tunability
摘要： An all-optical switch based on plasmonic metal–insulator–metal (MIM) waveguides and the Mach–Zehnder (MZ) interferometer is designed. In order to realize an all-optical and active switch, a nonlinear material with intensity-dependent refractive index is introduced in one arm. Other than studying a typical MZ structure, we also investigate the asymmetric case where unequal thicknesses and distances for MZ arms are proposed. The finite element method (FEM) with a refined triangle mesh is employed for simulations. Results for ON and OFF states are provided with or without employing the pump field. Investigation of the geometrical dispersion reveals tunability of the structure for specific frequencies in the terahertz region. Finally, we show that introducing asymmetric arms provides better tunability in the designed ultrafast nano-scale switch and suggests its potential applications in integrated optical circuits.
关键词： Nonlinear optical devices,Mach-Zehnder interferometer,Surface plasmon polaritons,Plasmonic switches
更新于2025-09-16 10:30:52
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Layered THz waveguides for SPPs, filter and sensor applications
摘要： Theory of five kinds of layered structure THz waveguides is presented. In these waveguides, the modified and hybrid THz surface plasmon-polaritons (SPPs) are researched in detail. On these modes, the effects of material in each layer are discussed. The anti-resonant reflecting mechanism is also discussed in these waveguides. The mode characteristics of both TM mode and TE mode are analyzed for guiding TM mode with low loss and TE modes with huge loss in one waveguide: the TE modes filter application is put forward. The mode characteristics for one waveguide have useful sensor applications: for TE1 mode, we find that the low cut-off frequency has a sensitivity (S) to the refractive index of the dielectric slab. The highest S can be 666.7 GHz/RIU when n2 = 1.5, w = 0 and t = 0.1 mm. We believe these results are very useful for designing practical THz devices for SPPs, filter and sensor applications.
关键词： Sensors,THz waveguides,Surface plasmon-polaritons,Filters
更新于2025-09-16 10:30:52
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[IEEE 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Munich, Germany (2019.6.23-2019.6.27)] 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Towards Near-Field Coupling of Surface Plasmon Polaritons across Few-Nanometer Gaps between two Laterally Tapered Gold Waveguides
摘要： Nanofocusing of light in combination with an efficient energy transfer of metallic nanostructures is a key task towards ultrafast, all-optical switching on the nanoscale. A possible realization of such a device is based on two tapered plasmonic nanostructures separated by a few-nanometer gap, in which information transport is controlled via strong coupling of the electromagnetic near-field and excitonic molecules in the gap region of the waveguides. The fabrication of such mesoscopic nanostructures that can concentrate free-propagating light to few-nanometers dimensions remains challenging due to the desired nanometer precision in the gap region. Here, we report on the fabrication of a plasmonic nanostructures consisting of a pair of both striped and tapered waveguides in 200 nm thick Au films with gap sizes and radii of curvature down to 11 nm using a Focused Ion Beam-based “Sketch and Peel” lithography process. Curved focused-ion beam written gratings in the waveguides enable the in- and out-coupling and focusing of surface plasmon polaritons into the nanostructure. The propagation of these SPPs is afterwards monitored using far-field confocal microscopy. We find a relatively constant transmission of light for large gap sizes, accompanied by a drastically increase for gap sizes below 20 nm. This increase for small gap sizes can be approximated best by fitting an exponential decay with a decay length of 8 nm suggesting a significant energy transport through near-field coupling of the two waveguides. These experimental findings are in accordance to finite element method and finite difference time domain calculations that show a strong localization of the electric field in the gap region of the two waveguides. The profound electric field strength and the spatial confinement of the electric fields suggest such plasmonic waveguides as prototypical structures for probing the strong coupling between propagating surface plasmon polaritons in adjacent, however separated plasmonic waveguides on one hand and between SPP waves and single quantum emitters that are placed in the gap region of the waveguides on the other hand. The realization of such coupling could enable the ultrafast, remote switching on the nanoscale.
关键词： ultrafast switching,nanofocusing,near-field coupling,surface plasmon polaritons,plasmonic nanostructures
更新于2025-09-16 10:30:52
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Electrocatalytic glycerol oxidation enabled by surface plasmon polariton-induced hot carriers in Kretschmann configuration
摘要： Plasmonic hot carrier generation has attracted increasing attention due to its ability to convert light to electrical energy. The generation of plasmon-induced hot carriers can be achieved via Landau damping in the non-radiative decay process of the plasmonic excitation energy. Localized surface plasmons (LSPs) undergo both radiative and non-radiative decays, while surface plasmon polaritons (SPPs) dissipate only via the non-radiative decay. Thus, it is a challenging task to exploit the surface plasmon polaritons for the efficient generation of hot carriers and their applications. In this study, a model hot-carrier-mediated electrocatalytic conversion system was demonstrated using an Au thin film in Kretschmann configuration, which is the representative platform to excite SPPs. AgPt-decorated Au nanobipyramids (AuNBPs) were designed and introduced onto the Au film, creating hot-spots to revolutionize the thin film-based photon-to-carrier conversion efficiency. The glycerol electro-oxidation reaction enabled by such SPP-induced hot carriers was evaluated and exhibited a photon-to-hot carrier conversion efficiency of 2.4 × 10?3%, which is ～2.5 times enhanced as compared to the efficiency based on the neat Au film.
关键词： Electrocatalytic glycerol oxidation,Surface plasmon polaritons,Au nanobipyramids,Plasmonic hot carrier generation,Kretschmann configuration
更新于2025-09-16 10:30:52
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Plasmonic nanosensor based on multiple independently tunable Fano resonances
摘要： A novel refractive index nanosensor with compound structures is proposed in this paper. It consists of three different kinds of resonators and two stubs which are side-coupled to a metal–dielectric–metal (MDM) waveguide. By utilizing numerical investigation with the finite element method (FEM), the simulation results show that the transmission spectrum of the nanosensor has as many as five sharp Fano resonance peaks. Due to their different resonance mechanisms, each resonance peak can be independently tuned by adjusting the corresponding parameters of the structure. In addition, the sensitivity of the nanosensor is found to be up to 1900 nm/RIU. For practical application, a legitimate combination of various different components, such as T-shaped, ring, and split-ring cavities, has been proposed which dramatically reduces the nanosensor dimensions without sacrificing performance. These design concepts pave the way for the construction of compact on-chip plasmonic structures, which can be widely applied to nanosensors, optical splitters, filters, optical switches, nonlinear photonic and slow-light devices.
关键词： metal–dielectric–metal (MDM) waveguide,nanosensor,on-chip plasmonic structures,Fano resonance,surface plasmon polaritons (SPPs)
更新于2025-09-16 10:30:52
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Nanoplasmonics - Fundamentals and Applications || Magneto‐Plasmonics and Optical Activity in Graphene‐Based Nanowires
摘要： Nowadays, graphene plasmonics shows a great number of features unusual for traditional (metal-based) plasmonics from high localization and large propagation distance of surface plasmon-polaritons (SPPs) through the existence of both TE- and TM-polarized SPPs to the possibility of controlled SPPs by graphene chemical potential (or, equivalently, by gate voltage or chemical doping). Cylindrical graphene-based plasmonic structures have some advantages in contrast to planar geometry: absence of edge losses, existence of high-order azimuthal modes, etc. In this work, we discuss some ways to obtain an optical activity in cylindrical graphene-based plasmonic structures and its possible applications to SPPs manipulation.
关键词： surface plasmon-polaritons,metasurface,graphene,magneto-plasmonics,optical activity
更新于2025-09-16 10:30:52
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A Multipurpose and Highly-Compact Plasmonic Filter based on Metal-Insulator-Metal Waveguides
摘要： A multipurpose and ultra-compact nanoplasmonic wavelength filter based on stub structure in a metal-insulator-metal (MIM) waveguide is suggested and numerically investigated. A novel approach of connecting two stepped-like apertures to both input and output ports is applied to form Fabry-Perot (FP) cavities, which enabled the structure to act as a dual band-pass filter at wavelengths 1310 nm and 1550 nm. It is shown that the variation in cavities’ length allows to realize a long-wavelength cutoff filter, and cutoff wavelength can be easily tuned by adjusting the length of the cavities. Furthermore, it is revealed that increasing the gap between the stepped-like apertures and the cavities provides a triple band-pass at telecom wavelengths, e.g. 1267.5nm, 1414.19 nm, and 1644.7 nm. The tunable broadband high-pass wavelength filter is then achieved while the lengths of stepped-like apertures and stub resonators are set to be identical. Finally, a tunable nearly perfect absorber can be obtained by varying the width of stub resonators. Therefore, because of functionality, size, as well as efficiency the proposed plasmonic filter may greatly contribute to miniaturization of next generation of photonic integrated circuits (PICs), and find applications in on-chip integration and wavelength-division multiplexing (WDM) in optical communication systems.
关键词： wavelength filtering devices,optical filters,Coupled resonators,photonic integrated circuits,surface plasmon polaritons,Fabry-Perot
更新于2025-09-16 10:30:52
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Plasmonic Jackiw-Rebbi Modes in Graphene Waveguide Arrays
摘要： We investigate the topological bound modes of surface plasmon polaritons (SPPs) in a graphene pair waveguide array. The arrays are with uniform inter-layer and intra-layer spacings but the chemical potential of two graphene in each pair are di?erent. The topological bound modes emerge when two arrays with opposite sequences of chemical potential are interfaced, which are analogous to Jackiw-Rebbi modes with opposite mass. We show the topological bound modes can be dynamically controlled by tuning the chemical potential, and the propagation loss of topological bound modes can be remarkably reduced by decreasing the chemical potential. Thanks to the strong con?nement of graphene SPPs, the modal wavelength of topological bound modes can be squeezed as small as 1/70 of incident wavelength. The study provides a promising approach to realizing robust light transport beyond di?raction limit.
关键词： surface plasmon polaritons,waveguide arrays,topological bound modes
更新于2025-09-16 10:30:52
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Detecting polarization state of arbitrary polarized light by chiral plasmonic lenses with distributed nanoslits
摘要： We devise three chiral plasmonic lenses (PLs) with distributed nanoslits for detecting the complete state of polarization of an arbitrary polarized light. A double-ring arrayed nanocrosses-based plasmonic lens is proposed to focus the surface plasmon polaritons excited by the two circularly polarized components of the incident light, thus enabling the phase difference between the two components to be retrieved. Two Archimedes-spiral arrayed nanoslits-based PLs with opposite chirality are designed to detect the relative strength of the two components. The focusing properties of the three structures are theoretically derived and numerically investigated, demonstrating the effectiveness of the proposed method.
关键词： surface plasmon polaritons,polarization state,nanoslits,chiral plasmonic lenses
更新于2025-09-16 10:30:52