scholarly journals Plasmon resonances of graphene-dielectric-metal structures calculated by the method of recurrence relations

Author(s):  
Gerardo Gonzalez de la Cruz ◽  
Maurice Oliva-Leyva

Abstract Graphene supports surface plasmons in the therahertz range, and compared with noble-metal plasmons, they show an extreme level of field confinement and relatively long propagation distances, with the advantage of being highly tunable via electrostatic field. Nevertheless, its interaction with light is normally rather weak. To obtain a more powerful capability of excite plasmons, a combination of graphene and artificial structures (metamaterials) present a powerful tunability for enhancing light-matter interaction. These features make graphene metamaterials a promising candidate for plasmonics and surface plasmon resonance for biological sensors. In this work, we study the plasmon spectra in a finite number of graphene layers on a metallic-dielectric substrate surrounded by materials with different dielectric constants. It is shown that using standard electromagnetic boundary conditions and solving the recurrence relation (a suitable alternative to transfer matrix method) for the coefficients of the electric potential between graphene layers, an explicit effective dielectric function of the metamaterial can be obtained giving the plasmon dispersion relations. It is found that the metal-dielectric-layered graphene structure supports both, high-energy optical plasmons oscillations and out-of-phase low energy acoustic charge density excitations. Experimentally, the Kretschmann configuration can be used to excite the surface plasmon resonances. It is based on the observation of a sharp minimum in the reflection coefficient versus angle (or wavelength) curve.

2014 ◽  
Vol 20 (3) ◽  
pp. 767-778 ◽  
Author(s):  
Edson P. Bellido ◽  
David Rossouw ◽  
Gianluigi A. Botton

AbstractEnergy resolution is one of the most important parameters in electron energy-loss spectroscopy. This is especially true for measurement of surface plasmon resonances, where high-energy resolution is crucial for resolving individual resonance peaks, in particular close to the zero-loss peak. In this work, we improve the energy resolution of electron energy-loss spectra of surface plasmon resonances, acquired with a monochromated beam in a scanning transmission electron microscope, by the use of the Richardson–Lucy deconvolution algorithm. We test the performance of the algorithm in a simulated spectrum and then apply it to experimental energy-loss spectra of a lithographically patterned silver nanorod. By reduction of the point spread function of the spectrum, we are able to identify low-energy surface plasmon peaks in spectra, more localized features, and higher contrast in surface plasmon energy-filtered maps. Thanks to the combination of a monochromated beam and the Richardson–Lucy algorithm, we improve the effective resolution down to 30 meV, and evidence of success up to 10 meV resolution for losses below 1 eV. We also propose, implement, and test two methods to limit the number of iterations in the algorithm. The first method is based on noise measurement and analysis, while in the second we monitor the change of slope in the deconvolved spectrum.


Nanophotonics ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 3965-3975 ◽  
Author(s):  
Dmitry Yu. Fedyanin ◽  
Alexey V. Krasavin ◽  
Aleksey V. Arsenin ◽  
Anatoly V. Zayats

AbstractPlasmonics offers a unique opportunity to break the diffraction limit of light and bring photonic devices to the nanoscale. As the most prominent example, an integrated nanolaser is a key to truly nanoscale photonic circuits required for optical communication, sensing applications and high-density data storage. Here, we develop a concept of an electrically driven subwavelength surface-plasmon-polariton nanolaser, which is based on a novel amplification scheme, with all linear dimensions smaller than the operational free-space wavelength λ and a mode volume of under λ3/30. The proposed pumping approach is based on a double-heterostructure tunneling Schottky barrier diode and gives the possibility to reduce the physical size of the device and ensure in-plane emission so that the nanolaser output can be naturally coupled to a plasmonic or nanophotonic waveguide circuitry. With the high energy efficiency (8% at 300 K and 37% at 150 K), the output power of up to 100 μW and the ability to operate at room temperature, the proposed surface plasmon polariton nanolaser opens up new avenues in diverse application areas, ranging from ultrawideband optical communication on a chip to low-power nonlinear photonics, coherent nanospectroscopy, and single-molecule biosensing.


Nanophotonics ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 975-982
Author(s):  
Huanhuan Su ◽  
Shan Wu ◽  
Yuhan Yang ◽  
Qing Leng ◽  
Lei Huang ◽  
...  

AbstractPlasmonic nanostructures have garnered tremendous interest in enhanced light–matter interaction because of their unique capability of extreme field confinement in nanoscale, especially beneficial for boosting the photoluminescence (PL) signals of weak light–matter interaction materials such as transition metal dichalcogenides atomic crystals. Here we report the surface plasmon polariton (SPP)-assisted PL enhancement of MoS2 monolayer via a suspended periodic metallic (SPM) structure. Without involving metallic nanoparticle–based plasmonic geometries, the SPM structure can enable more than two orders of magnitude PL enhancement. Systematic analysis unravels the underlying physics of the pronounced enhancement to two primary plasmonic effects: concentrated local field of SPP enabled excitation rate increment (45.2) as well as the quantum yield amplification (5.4 times) by the SPM nanostructure, overwhelming most of the nanoparticle-based geometries reported thus far. Our results provide a powerful way to boost two-dimensional exciton emission by plasmonic effects which may shed light on the on-chip photonic integration of 2D materials.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Md Atiqur Rahman ◽  
Mohammad Tariqul Islam ◽  
Mandeep Singh Jit Singh ◽  
Md Samsuzzaman ◽  
Muhammad E. H. Chowdhury

AbstractIn this article, we propose SNG (single negative) metamaterial fabricated on Mg–Zn ferrite-based flexible microwave composites. Firstly, the flexible composites are synthesized by the sol-gel method having four different molecular compositions of MgxZn(1−x)Fe2O4, which are denoted as Mg20, Mg40, Mg60, and Mg80. The structural, morphological, and microwave properties of the synthesized flexible composites are analyzed using X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), and conventional dielectric assessment kit (DAK) to justify their possible application as dielectric substrate at microwave frequency regime. Thus the average grain size is found from 20 to 24 nm, and the dielectric constants are 6.01, 5.10, 4.19, and 3.28, as well as loss tangents, are 0.002, 0.004, 0.006, and 0.008 for the prepared Mg–Zn ferrites, i.e., Mg20, Mg40, Mg60, and Mg80 respectively. Besides, the prepared low-cost Mg–Zn ferrite composites exhibit high flexibility and lightweight, which makes them a potential candidate as a metamaterial substrate. Furthermore, a single negative (SNG) metamaterial unit cell is fabricated on the prepared, flexible microwave composites, and their essential electromagnetic behaviors are observed. Very good effective medium ratios (EMR) vales are obtained from 14.65 to 18.47, which ensure the compactness of the fabricated prototypes with a physical dimension of 8 × 6.5 mm2. Also, the proposed materials have shown better performances comparing with conventional FR4 and RO4533 materials, and they have covered S-, C-, X-, Ku-, and K-band of microwave frequency region. Thus, the prepared, flexible SNG metamaterials on MgxZn(1−x)Fe2O4 composites are suitable for microwave and flexible technologies.


2021 ◽  
Author(s):  
Xiaomin Zhao ◽  
Chenglin Du ◽  
Rong Leng ◽  
Li Li ◽  
Weiwei Luo ◽  
...  

Plasmon resonances with high-quality are of great importance in light emission control and light-matter interaction. Nevertheless, the inherent Ohmic and radiative losses usually hinder the plasmon performance of the metallic...


Plasmonics ◽  
2013 ◽  
Vol 8 (3) ◽  
pp. 1379-1385 ◽  
Author(s):  
Kristof Lodewijks ◽  
Jef Ryken ◽  
Willem Van Roy ◽  
Gustaaf Borghs ◽  
Liesbet Lagae ◽  
...  

2001 ◽  
Vol 708 ◽  
Author(s):  
Keizo Kato ◽  
Futoshi Takahashi ◽  
Kazunari Shinbo ◽  
Futao Kaneko ◽  
Takashi Wakamatsu

ABSTRACTShort-circuit photocurrents (ISC) due to surface plasmon (SP) excitations have been investigated for the photoelectric cells using Langmuir-Blodgett (LB) films of merocyanine (MC) dye. The MC dye exhibits p-type conduction, and the Schottky and Ohmic contacts are obtained at the interfaces between MC LB films and Al thin films and between MC LB films and Ag thin films, respectively. Since the Schottky diodes show the photoelectric effects, the Schottky photoelectric cells have been constructed. The cells with two kinds of structures, that is, prism/Al/MC/Ag (type I) and prism/MgF2/Al/MC/Ag (type II), have been prepared. In the attenuated total reflection (ATR) method, the types I and II have the Kretschmann and both the Kretschmann and Otto configurations, respectively. SP has been resonantly excited at the interface between Ag and air for the type I and at the interfaces between MgF2 and Al between Ag and air for the type II. The ATR and the ISC properties have been simultaneously measured as a function of the incident angles of the laser beams. The peaks of the ISC have corresponded to the resonant angles of the ATR curves. The electric fields and optical absorptions in the cells have been also calculated using the dielectric constants and the film thicknesses obtained from the ATR measurements. The calculated absorptions in the MC layers as a function of the incident angles have corresponded to the results of ISC. It has been estimated that the ISC for both types I and II could be enhanced by the excitations of SP in the ATR configurations.


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