scholarly journals Design of Surface Plasmon Nanolaser Based on MoS2

2018 ◽  
Vol 8 (11) ◽  
pp. 2110 ◽  
Author(s):  
Litu Xu ◽  
Fang Li ◽  
Lai Wei ◽  
Jianxin Zhou ◽  
Shuai Liu
Keyword(s):  
High Field ◽  
Electric Field Distribution ◽  
Propagation Loss ◽  
Comsol Multiphysics ◽  
Lasing Threshold ◽  
Optimal Parameters ◽  
The Finite Element Method ◽  
Low Loss ◽  
Low Threshold ◽  
Simulation Results

The paper has proposed a new structure based on MoS2. The electric field distribution, the locality and the loss of the mode, and the threshold under different geometric shapes and parameters are investigated using COMSOL Multiphysics software, based on the finite element method. The different influenced degree of each component is also analyzed. Simulation results reveal that this kind of nanolaser has a low loss and high field confinement ability, the radius of CdS and Ag make a major contribution to the low loss and low threshold, and field confinement ability is mainly affected by the height of air gap. Under optimal parameters, effective propagation loss is only 0.00013, and the lasing threshold can be as low as 0.11 μm−1. The results provide theory and technique support to the field of new nanolaser design.

scholarly journals Low Threshold Plasmonic Nanolaser Based on Graphene

2018 ◽  
Vol 8 (11) ◽  
pp. 2186 ◽  
Author(s):  
Litu Xu ◽  
Fang Li ◽  
Shuai Liu ◽  
Fuqiang Yao ◽  
Yahui Liu
Keyword(s):  
Model Simulation ◽  
Geometric Model ◽  
Propagation Loss ◽  
Lasing Threshold ◽  
Metal Loss ◽  
Model Parameters ◽  
Hybrid Plasma ◽  
Low Threshold ◽  
Mode Area ◽  
Plasmonic Nanolaser

A hybrid plasmonic nanolaser based on nanowire/air slot/semicircular graphene and metal wire structure was designed. In this structure, the waveguides in the nanowires and the graphene-metal interface are coupled to form a hybrid plasma mode, which effectively reduces the metal loss. The mode and strong coupling of the laser are analyzed by using the finite-element method. Its electric field distribution, propagation loss, normalized mode area, quality factor, and lasing threshold are studied with the different geometric model. Simulation results reveal that the performance of the laser using this structure can be optimized by adjusting the model parameters. Under the optimal parameters, the effective propagation loss is only 0.0096, and the lasing threshold can be as low as 0.14 μm−1. This structure can achieve deep sub-wavelength confinement and low-loss transmission, and provides technical support for the miniaturization and integration of nano-devices.

scholarly journals DEVELOPMENT OF PLANAR ELECTRODES FOR REAL-TIME ELECTROPORATION / PLANARIŲJŲ ELEKTRODŲ MODELIS REALIOJO LAIKO ELEKTROPORACIJOS TYRIMAMS

2018 ◽  
Vol 10 (0) ◽  
pp. 1-4
Author(s):  
Paulius Butkus
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Real Time ◽  
Electric Field Distribution ◽  
Fem Analysis ◽  
Comsol Multiphysics ◽  
Homogeneous Cell ◽  
Simulation Results ◽  
Planar Electrodes ◽  
Microscope Stage

In this paper the concept of planar electrodes for real-time electroporation on a microscope stage is presented and the structure is analyzed using finite element method (FEM) analysis. A multiparametric investigation of the chip topology is performed in COMSOL Multiphysics environment to define the configuration of electrodes, electric field distribution and other electroporation parameters to ensure a homogeneous cell exposure. Based on the simulation results, an optimal electrode configuration, which is suitable for the investigation of the permeabilization thresholds during electroporation, is proposed.

Footprint Analysis of CMOS Compatible Silicon-on-Insulator based Photonic Waveguides

2020 ◽  
Vol 12 ◽  
Author(s):  
Veer Chandra ◽  
Rakesh Ranjan
Keyword(s):  
Silicon On Insulator ◽  
Propagation Loss ◽  
Comsol Multiphysics ◽  
The Finite Element Method ◽  
Propagation Length ◽  
Footprint Analysis ◽  
Photonic Waveguides ◽  
Cmos Compatible ◽  
The Impact ◽  
Slot Waveguides

Aim: Establish the efficient footprint size, i.e., the total substrate width of photonic waveguides (Ridge, Rib, and Slot) under the fundamental mode propagation constraints. Objective: By varying the total substrate width for all photonic waveguides (Ridge, Rib, and Slot) with respect to four major waveguide parameters, namely effective refractive index, propagation loss, propagation length, and confinement percentage, the converged values of these waveguide parameters have to be obtained. Methods: The finite element method (FEM) based simulations, using the COMSOL Multiphysics, have been used to study the modal characteristics of photonic waveguides to achieve their efficient footprint size. Results: The total substrate widths have been obtained for the all four parameters and considering the impact of all these waveguide parameters simultaneously, the efficient total substrate width have been recognized as 2500 nm, 4000 nm, and 3000 nm, respectively for Ridge, Rib, and Slot waveguides. Conclusion: The efficient waveguide footprints, i.e., the total substrate widths for the three photonic waveguides, namely Ridge, Rib and Slot waveguides have been established.

scholarly journals Recent simulation results of the magnetic induction tomography forward problem

2016 ◽  
Vol 65 (2) ◽  
pp. 327-336 ◽  
Author(s):  
Krzysztof Stawicki ◽  
Beata Szuflitowska ◽  
Marcin Ziolkowski
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Magnetic Induction ◽  
Forward Problem ◽  
Comsol Multiphysics ◽  
The Finite Element Method ◽  
Commercial Software ◽  
Simulation Results ◽  
Magnetic Induction Tomography ◽  
Computer Resources

Abstract In this paper we present the results of simulations of the Magnetic Induction Tomography (MIT) forward problem. Two complementary calculation techniques have been implemented and coupled, namely: the finite element method (applied in commercial software Comsol Multiphysics) and the second, algebraic manipulations on basic relationships of electromagnetism in Matlab. The developed combination saves a lot of time and makes a better use of the available computer resources.

Low Loss Hybrid Dielectric-Metal-Dielectric Waveguides for Sub-Micron Mode Confinement and Efficient Directional Coupling

2012 ◽  
Vol 476-478 ◽  
pp. 839-842
Author(s):  
Mo Yang ◽  
Jin Cheng Song
Keyword(s):  
Propagation Loss ◽  
Geometrical Parameters ◽  
Dielectric Waveguides ◽  
The Finite Element Method ◽  
Low Loss ◽  
Electro Optic ◽  
Integrated Optical ◽  
Integrated Optical Devices ◽  
Mode Size ◽  
High Dielectric

In this paper, we present the design of a novel hybrid dielectric-metal-dielectric waveguide, which consists of a metal stripe sandwiched between low-high dielectric layers. Its modal characteristics are investigated using the finite element method at the telecom wavelength. Simulations show that the dielectric contrast near the metal stripe results in a strongly confined hybrid plasmonic mode with sub-micron mode size and low propagation loss. The effects of geometrical parameters are analyzed systematically and the properties of directional couplers based on such hybrid waveguide are also investigated. The proposed structure could be useful candidates for various integrated optical devices and enable many applications such as electro-optic modulation, switching, sensing and more.

An Investigation of the Distribution of Electric Potential and Space Charge in a Silicon Nanowire

2014 ◽  
Vol 69 (10-11) ◽  
pp. 597-605 ◽  
Author(s):  
A. Wesam Al-Mufti ◽  
Uda Hashim ◽  
Md. Mijanur Rahman ◽  
Tijjani Adam
Keyword(s):  
Finite Element Method ◽  
Space Charge ◽  
Electric Potential ◽  
Silicon Nanowire ◽  
Electrical Potential ◽  
Comsol Multiphysics ◽  
The Finite Element Method ◽  
Simulation Experiments ◽  
Different Dimensions

AbstractThe distribution of electric potential and space charge in a silicon nanowire has been investigated. First, a model of the nanowire is generated taking into consideration the geometry and physics of the nanowire. The physics of the nanowire was modelled by a set of partial differential equations (PDEs) which were solved using the finite element method (FEM). Comprehensive simulation experiments were performed on the model in order to compute the distribution of potential and space charge. We also determined, through simulation, how the characteristic of the nanowire is affected by its dimensions. The characterization of the resulting nanowire, calculated by COMSOL Multiphysics, shows different dimensions and their effect on space charge and electrical potential

FEMLIB: An Object-Oriented Framework for Optimization and Simulation

1995 ◽  
Author(s):  
Michael M. Tiller ◽  
Jonathan A. Dantzig
Keyword(s):  
Material Properties ◽  
Object Oriented ◽  
The Finite Element Method ◽  
Simulation And Optimization ◽  
Gradient Based ◽  
Level Problem ◽  
Simulation Results ◽  
Optimization And Simulation ◽  
High Level ◽  
Simulation Parameters

Abstract In this paper we discuss the design of an object-oriented framework for simulation and optimization. Although oriented around high-level problem solving, the framework defines several classes of problems and includes concrete implementations of common algorithms for solving these problems. Simulations are run by combining these algorithms, as needed, for a particular problem. Included in this framework is the capability to compute the sensitivity of simulation results to the different simulation parameters (e.g. material properties, boundary conditions, etc). This sensitivity information is valuable in performing optimization because it allows the use of gradient-based optimization algorithms. Also included in the system are many useful abstractions and implementations related to the finite element method.

A Two Step Damage Prognosis Method for Beam-Like Truss Structures

2014 ◽  
Vol 578-579 ◽  
pp. 1092-1095
Author(s):  
Hao Kai Jia ◽  
Ling Yu
Keyword(s):  
Finite Element Method ◽  
Strain Energy ◽  
Truss Structure ◽  
Truss Structures ◽  
Second Step ◽  
The Finite Element Method ◽  
Modal Strain Energy ◽  
Damage Prognosis ◽  
Modal Curvature ◽  
Simulation Results

In this study, a two step damage prognosis method is proposed for beam-like truss structures via combining modal curvature change (MCC) with modal strain energy change ratio (MSECR). Changes in the modal curvature and the elemental strain energy are selected as the indicator of damage prognosis. Different damage elements with different damage degrees are simulated. In the first step, the finite element method is used to model a beam-like truss structure and the displacement modes are got. The damage region is estimated by the MCC of top and bottom chords of a beam-like truss structure. In the second step, the elemental MSECR in the damage region is calculated and the maximum MSECR element is deemed as the damage element. The simulation results show that this method can accurately locate the damage in the beam-like truss structure.

scholarly journals Long Low-Loss-Litium Niobate on Insulator Waveguides with Sub-Nanometer Surface Roughness

Nanomaterials ◽  
2018 ◽  
Vol 8 (11) ◽  
pp. 910 ◽  
Author(s):  
Rongbo Wu ◽  
Min Wang ◽  
Jian Xu ◽  
Jia Qi ◽  
Wei Chu ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Integrated Circuits ◽  
Large Scale ◽  
Photonic Integrated Circuits ◽  
Surface Patterning ◽  
Propagation Loss ◽  
Direct Writing ◽  
Laser Direct Writing ◽  
Low Loss ◽  
Atomic Force

In this paper, we develop a technique for realizing multi-centimeter-long lithium niobate on insulator (LNOI) waveguides with a propagation loss as low as 0.027 dB/cm. Our technique relies on patterning a chromium thin film coated on the top surface of LNOI into a hard mask with a femtosecond laser followed by chemo-mechanical polishing for structuring the LNOI into the waveguides. The surface roughness on the waveguides was determined with an atomic force microscope to be 0.452 nm. The approach is compatible with other surface patterning technologies, such as optical and electron beam lithographies or laser direct writing, enabling high-throughput manufacturing of large-scale LNOI-based photonic integrated circuits.

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