Symmetric Graphene Dielectric Nanowaveguides as Ultra-Compact Photonic Structures

A symmetric graphene plasmon waveguide (SGPWG) is proposed here to achieve excellent subwavelength waveguiding performance of mid-infrared waves. The modal properties of the fundamental graphene plasmon mode are investigated by use of the finite element method. Due to the naturally rounded tips, the plasmon mode in SGPWG could achieve a normalized mode field area of ~10−5 (or less) and a figure of merit over 400 by tuning the key geometric structure parameters and the chemical potential of graphene. In addition, results show that the modal performance of SGPWG seems to improve over its circular counterparts. Besides the modal properties, crosstalk analysis indicates that the proposed waveguide exhibits extremely low crosstalk, even at a separation distance of 64 nm. Due to these excellent characteristics, the proposed waveguide has promising applications in ultra-compact integrated photonic components and other intriguing nanoscale devices.

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Theoretical Analysis of Terahertz Dielectric–Loaded Graphene Waveguide

Nanomaterials ◽

10.3390/nano11010210 ◽

2021 ◽

Vol 11 (1) ◽

pp. 210

Author(s):

Da Teng ◽

Kai Wang

Keyword(s):

Photonic Devices ◽

Effective Index ◽

The Finite Element Method ◽

Index Method ◽

Modal Properties ◽

Terahertz Region ◽

Effective Index Method ◽

Integration Density ◽

Device Integration ◽

Potential Applications

The waveguiding of terahertz surface plasmons by a GaAs strip-loaded graphene waveguide is investigated based on the effective-index method and the finite element method. Modal properties of the effective mode index, modal loss, and cut-off characteristics of higher order modes are investigated. By modulating the Fermi level, the modal properties of the fundamental mode could be adjusted. The accuracy of the effective-index method is verified by a comparison between the analytical results and numerical simulations. Besides the modal properties, the crosstalk between the adjacent waveguides, which determines the device integration density, is studied. The findings show that the effective-index method is highly valid for analyzing dielectric-loaded graphene plasmon waveguides in the terahertz region and may have potential applications in subwavelength tunable integrated photonic devices.

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High Sensitivity Plasmonic Sensor Based on Fano Resonance with Inverted U-Shaped Resonator

Sensors ◽

10.3390/s21041164 ◽

2021 ◽

Vol 21 (4) ◽

pp. 1164

Author(s):

Gongli Xiao ◽

Yanping Xu ◽

Hongyan Yang ◽

Zetao Ou ◽

Jianyun Chen ◽

...

Keyword(s):

Fano Resonance ◽

Figure Of Merit ◽

High Sensitivity ◽

Refractive Index Sensor ◽

Multimode Interference ◽

Geometrical Parameters ◽

The Finite Element Method ◽

Plasmonic Sensor ◽

Coupled Mode ◽

Plasmonic Nanosensor

Herein, we propose a tunable plasmonic sensor with Fano resonators in an inverted U-shaped resonator. By manipulating the sharp asymmetric Fano resonance peaks, a high-sensitivity refractive index sensor can be realized. Using the multimode interference coupled-mode theory and the finite element method, we numerically simulate the influences of geometrical parameters on the plasmonic sensor. Optimizing the structure parameters, we can achieve a high plasmonic sensor with the maximum sensitivity for 840 nm/RIUand figure of merit for 3.9 × 105. The research results provide a reliable theoretical basis for designing high sensitivity to the next generation plasmonic nanosensor.

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Design and analysis of trench-assisted large-mode-field-area multi-core fiber with air-hole

Applied Physics B ◽

10.1007/s00340-020-07557-7 ◽

2021 ◽

Vol 127 (1) ◽

Author(s):

Yuqin Zhang ◽

Yudong Lian ◽

Yuhe Wang ◽

Jingbo Wang ◽

Mengxin Yang ◽

...

Keyword(s):

Mode Field ◽

Core Fiber ◽

Field Area ◽

Air Hole

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Study of Birefringence and Mode Field for Hollow-Core Photonic Bandgap Fiber

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.609-610.324 ◽

2014 ◽

Vol 609-610 ◽

pp. 324-329

Author(s):

Li Shuang Feng ◽

Wen Shuai Song ◽

Xiao Yuan Ren

Keyword(s):

Field Distribution ◽

Photonic Bandgap ◽

Surface Mode ◽

Hollow Core ◽

The Finite Element Method ◽

Core Mode ◽

Photonic Bandgap Fiber ◽

Mode Field ◽

Air Core ◽

Polarization Maintaining

Since the Appearance of Hollow-Core Photonic Bandgap Fiber (HC-PBF), it was Widely Concerned for its Excellent Characteristics. in Order to Study the Characteristics of the HC-PBF that can be Used in Resonator Fiber Optic Gyros (R-Fogs), the Model Structure of a Polarization-Maintaining HC-PBF was Built and its Performance was Simulated by Using the Finite Element Method (FEM). its Mode Field Distribution and Birefringence Characteristics were Obtained. the Influences of the Air Core and Cladding Structures on the Mode Field Distribution and Birefringence were Simulated and Analyzed Further. the Result Showed that there are both Core Mode and Surface Mode in the Structure we Built. by Adding Scattering Points into the Fiber Core, the Surface Mode can be Significantly Suppressed. by Matching the Size of Core and Air Holes around the Core, a Birefringence up to 8*10-4 were Obtained.

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A Nanoscale Structure Based on an MIM Waveguide Coupled with a Q Resonator for Monitoring Trace Element Concentration in the Human Body

Micromachines ◽

10.3390/mi12111384 ◽

2021 ◽

Vol 12 (11) ◽

pp. 1384

Author(s):

Tingsong Li ◽

Shubin Yan ◽

Pengwei Liu ◽

Xiaoyu Zhang ◽

Yi Zhang ◽

...

Keyword(s):

Human Body ◽

Figure Of Merit ◽

Refractive Index Sensor ◽

The Finite Element Method ◽

Transmission Characteristics ◽

Metal Insulator Metal ◽

Potential Applications ◽

Internal Mechanism ◽

Nanoscale Structure ◽

Mim Waveguide

In this study, a nano-refractive index sensor is designed that consists of a metal–insulator–metal (MIM) waveguide with a stub-1 and an orthogon ring resonator (ORR) with a stub-2. The finite element method (FEM) was used to analyze the transmission characteristics of the system. We studied the cause and internal mechanism of Fano resonance, and optimized the transmission characteristics by changing various parameters of the structure. In our experimental data, the suitable sensitivity could reach 2260 nm/RIU with a figure of merit of 211.42. Furthermore, we studied the detection of the concentration of trace elements (such as Na+) of the structure in the human body, and its sensitivity reached 0.505 nm/mgdL−1. The structure may have other potential applications in sensors.

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Iterative Blade Element Momentum Theory for Predicting Coaxial Rotor Performance in Hover

Journal of the American Helicopter Society ◽

10.4050/jahs.65.042005 ◽

2020 ◽

Vol 65 (4) ◽

pp. 1-12

Author(s):

Seongkyu Lee ◽

Maxime Dassonville

Keyword(s):

Figure Of Merit ◽

Measurement Data ◽

Separation Distance ◽

Blade Element Momentum Theory ◽

Momentum Theory ◽

Coaxial Rotor ◽

Aerodynamic Properties ◽

Induced Velocity ◽

Empirical Constants ◽

Blade Element

This paper presents a new blade element momentum theory (BEMT) for a coaxial rotor in hover. The new BEMT iteratively solves the upper and lower rotor induced velocities to account for the mutual rotor-to-rotor interaction. The upper rotor induced velocity is affected by the lower rotor thrust and induced velocity, whereas the lower rotor induced velocity is affected by the upper rotor thrust and induced velocity. Two empirical constants are included in each rotor calculation. This new BEMT provides the performance of each rotor as a function of the rotor separation distance. The new BEMT is validated with measurement data for two coaxial rotor experiments. The first experiment validates the thrust to power coefficients at a given separation distance. The second experiment validates each rotor's figure of merit, thrust, power, interference loss factors, etc. as a function of the rotor separation distance. It is shown that the BEMT captures the trends and magnitudes of the performance as a function of the rotor separation distance compared to the measurement data. Detailed radial distributions of aerodynamic properties are also presented at several separation distances.

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Graphene-Coated Elliptical Nanowires for Low Loss Subwavelength Terahertz Transmission

Applied Sciences ◽

10.3390/app9112351 ◽

2019 ◽

Vol 9 (11) ◽

pp. 2351 ◽

Cited By ~ 7

Author(s):

Da Teng ◽

Kai Wang ◽

Zhe Li ◽

Yongzhe Zhao ◽

Gao Zhao ◽

...

Keyword(s):

Chemical Potential ◽

Infrared Range ◽

Support Surface ◽

Low Loss ◽

Propagation Length ◽

Promising Alternative ◽

Mid Infrared ◽

Terahertz Transmission ◽

Mode Area ◽

Thz Waves

Graphene has been recently proposed as a promising alternative to support surface plasmons with its superior performances in terahertz and mid-infrared range. Here, we propose a graphene-coated elliptical nanowire (GCENW) structure for subwavelength terahertz waveguiding. The mode properties and their dependence on frequency, nanowire size, permittivity and chemical potential of graphene are studied in detail by using a finite element method, they are also compared with the graphene-coated circular nanowires (GCCNWs). Results showed that the ratio of the long and short axes (b/a) of the elliptical nanowire had significant influence on mode properties, they also showed that a propagation length over 200 μm and a normalized mode area of approximately 10−4~10−3 could be obtained. Increasing b/a could simultaneously achieve both long propagation length and very small full width at half maximum (FWHM) of the focal spots. When b/a = 10, a pair of focal spots about 40 nm could be obtained. Results also showed that the GCENW had a better waveguiding performance when compared with the corresponding GCCNWs. The manipulation of Terahertz (THz) waves at a subwavelength scale using graphene plasmon (GP) may lead to applications in tunable THz components, imaging, and nanophotonics.

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Mode Conversion of the Edge Modes in the Graphene Double-Ribbon Bend

Materials ◽

10.3390/ma12234008 ◽

2019 ◽

Vol 12 (23) ◽

pp. 4008

Author(s):

Lanlan Zhang ◽

Binghan Xue ◽

Yueke Wang

Keyword(s):

Finite Element Method ◽

Finite Element ◽

Surface Plasmons ◽

Mode Conversion ◽

Infrared Range ◽

The Finite Element Method ◽

Edge Mode ◽

Mid Infrared ◽

Graphene Surface ◽

Graphene Surface Plasmons

In this paper, a new kind of graphene double-ribbon bend structure, which can support two edge graphene surface plasmons (EGSPs) modes, is proposed. In this double-ribbon bend, one edge mode can be partly converted into another one. We attribute the mode conversion mechanism to the interference between the two edge plasmonic modes. Based on the finite element method (FEM), we calculate the transmission and loss of EGSPs propagating along this graphene double-ribbon bend in the mid-infrared range under different parameters.

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Analytical relation between effective mode field area and waveguide dispersion in microstructure fibers

Optics Letters ◽

10.1364/ol.31.003249 ◽

2006 ◽

Vol 31 (22) ◽

pp. 3249 ◽

Cited By ~ 7

Author(s):

Mathias Moenster ◽

Günter Steinmeyer ◽

Rumen Iliew ◽

Falk Lederer ◽

Klaus Petermann

Keyword(s):

Analytical Relation ◽

Mode Field ◽

Waveguide Dispersion ◽

Field Area

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Applications Of Tunable Mid-Infrared Plasmonic Square-Nanoring Resonator Based On Graphene Nanoribbon

10.21203/rs.3.rs-497948/v1 ◽

2021 ◽

Author(s):

Morteza Janfaza ◽

Mohammad Ali Mansouri-Birjandi ◽

Alireza Tavousi

Keyword(s):

Chemical Potential ◽

Graphene Nanoribbons ◽

Fdtd Method ◽

Three Dimensional ◽

Optical Computing ◽

Band Pass Filter ◽

Pass Filter ◽

Mid Infrared ◽

Band Pass ◽

Basic Blocks

Abstract In this work, different structures are designed based on graphene square-nanoring resonator (GSNR) and simulated by the three-dimensional finite-difference time-domain (3D-FDTD) method. Depending on the location and number of graphene nanoribbons (GNR), the proposed structures can be utilized as a band-pass filter, wavelength demultiplexer, or power splitter in the mid-infrared (MIR) wavelengths. The tunability of the suggested assemblies is easily controlled by changing the dimensions and/or the chemical potential of the GSNRs. Benefiting from the nanoscale and ultra-compact GNRs, these structures can be proposed as basic blocks for optical computing and signal processing in the MIR region.

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