Metallic Ellipsoidal Array – Film for Enhancing Transmission via Plasmonic Coupling

2014 ◽  
Vol 548-549 ◽  
pp. 393-396
Author(s):  
Ying Hu ◽  
Gui Qiang Liu ◽  
Xiang Nan Zhang ◽  
Yuan Hao Chen ◽  
Zheng Jie Cai ◽  
...  
Keyword(s):  
Slow Light ◽  
Fdtd Method ◽  
Three Dimensional ◽  
Metal Structure ◽  
Transparent Conductors ◽  
Long Wavelength ◽  
Highly Sensitive ◽  
Highly Sensitive Sensors ◽  
Difference Time ◽  
Sub Wavelength

In this paper, a novel metal structure that integrates double continuous Au films and double aligned gold (Au) non-close-packed ellipsoidal nanoparticle arrays is proposed. The optical features of this structure are simulated by using the three-dimensional finite-difference time-domain (3D-FDTD) method. Bimodal plasmonic resonances with the highest transmission up to 74% and 66% (corresponding to the short and long-wavelength, respectively) are achieved. This proposed structure with sub-wavelength size may provide fascinating applications in optoelectronic devices such as transparent conductors and conductive devices, slow light devices, highly sensitive sensors.

scholarly journals Tunable Mid-Infrared Graphene Plasmonic Cross-Shaped Resonator for Demultiplexing Application

2020 ◽  
Vol 10 (3) ◽  
pp. 1193 ◽  
Author(s):  
Somayyeh Asgari ◽  
Tapio Fabritius
Keyword(s):  
Fdtd Method ◽  
Three Dimensional ◽  
Single Mode ◽  
Transmission Spectra ◽  
Mid Infrared ◽  
Coupled Mode ◽  
Light Waves ◽  
Dimensional Parameters ◽  
Difference Time ◽  
Sub Wavelength

In this study, a tunable graphene plasmonic filter and a two-channel demultiplexer are proposed, simulated, and analyzed in the mid-infrared (MIR) region. We discuss the optical transmission spectra of the proposed cross-shaped resonator and the two-channel demultiplexer. The transmission spectra of the proposed MIR resonator are tunable by change of its dimensional parameters and the Fermi energy of the graphene. Our proposed structures have a single mode in the wavelength range of 5–12 µm. The minimum full width at half maximum (FWHM) and the maximum transmission ratio of the proposed resonator respectively reached 220 nm and 55%. Simulations are performed by use of three-dimensional finite-difference time-domain (3D-FDTD) method. Coupled mode theory (CMT) is used to investigate the structure theoretically. The numerical and the theoretical results are in good agreement. The performance of the proposed two-channel demultiplexer is investigated based on its crosstalk. The minimum value of crosstalk reaches −48.30 dB. Our proposed structures are capable of providing sub-wavelength confinement of light waves, useful in applications in MIR region.

scholarly journals Fully three-dimensional analysis of a photonic crystal assisted silicon on insulator waveguide bend

2018 ◽  
Vol 32 (31) ◽  
pp. 1850344 ◽  
Author(s):  
N. Eti ◽  
Z. Çetin ◽  
H. S. Sözüer
Keyword(s):  
Photonic Crystal ◽  
Numerical Study ◽  
Fdtd Method ◽  
Three Dimensional ◽  
Silicon On Insulator ◽  
Geometrical Parameters ◽  
Low Loss ◽  
Bending Loss ◽  
Difference Time ◽  
Waveguide Bend

A detailed numerical study of low-loss silicon on insulator (SOI) waveguide bend is presented using the fully three-dimensional (3D) finite-difference time-domain (FDTD) method. The geometrical parameters are optimized to minimize the bending loss over a range of frequencies. Transmission results for the conventional single bend and photonic crystal assisted SOI waveguide bend are compared. Calculations are performed for the transmission values of TE-like modes where the electric field is strongly transverse to the direction of propagation. The best obtained transmission is over 95% for TE-like modes.

Q-BOR–FDTD method for solving Schrodinger equation for rotationally symmetric nanostructures with hydrogenic impurity

2022 ◽  
Author(s):  
Arezoo Firoozi ◽  
Ahmad Mohammadi ◽  
Reza Khordad ◽  
Tahmineh Jalali
Keyword(s):  
Schrödinger Equation ◽  
Analytical Solutions ◽  
Schrodinger Equation ◽  
Fdtd Method ◽  
Three Dimensional ◽  
Test Cases ◽  
Body Of Revolution ◽  
Hydrogenic Impurity ◽  
Rotationally Symmetric ◽  
Difference Time

Abstract An efficient method inspired by the traditional body of revolution finite-difference time-domain (BOR-FDTD) method is developed to solve the Schrodinger equation for rotationally symmetric problems. As test cases, spherical, cylindrical, cone-like quantum dots, harmonic oscillator, and spherical quantum dot with hydrogenic impurity are investigated to check the efficiency of the proposed method which we coin as Quantum BOR-FDTD (Q-BOR-FDTD) method. The obtained results are analysed and compared to the 3-D FDTD method, and the analytical solutions. Q-BOR-FDTD method proves to be very accurate and time and memory efficient by reducing a three-dimensional problem to a two-dimensional one, therefore one can employ very fine meshes to get very precise results. Moreover, it can be exploited to solve problems including hydrogenic impurities which is not an easy task in the traditional FDTD calculation due to singularity problem. To demonstrate its accuracy, we consider spherical and cone-like core-shell QD with hydrogenic impurity. Comparison with analytical solutions confirms that Q-BOR–FDTD method is very efficient and accurate for solving Schrodinger equation for problems with hydrogenic impurity

Characteristics of Slow Light in a Photonic Crystal Coupled-Cavity Waveguide

2014 ◽  
Vol 887-888 ◽  
pp. 437-441
Author(s):  
Chang Xin Zhang ◽  
Xing Sheng Xu ◽  
Wei Xi
Keyword(s):  
Photonic Crystal ◽  
Group Velocity ◽  
Time Domain ◽  
Finite Difference Time Domain ◽  
Slow Light ◽  
Fdtd Method ◽  
Photonic Crystal Waveguide ◽  
Difference Time ◽  
Coupled Cavity ◽  
Coupled Cavity Waveguide

A two-dimensional (2D) triangular lattice photonic crystal coupled-cavity waveguide is designed and optimized. The transmission spectrum of the PC waveguide with TE polarization is calculated by using the finite-difference time-domain (FDTD) method, and the group velocity of c/131.18 at the wavelength is obtained. Through optimizing the parameters of photonic crystal waveguide, different resonance length are obtained by changing the number of the continous air holes. The smallest group velocity is obtained to be c/2209 in the coupled-cavity waveguide with 15 air holes. The mechanism of slow light in the coupled-cavity waveguide of photonic crystal is analyzed.

A SILVER-COATED SINUSOIDAL SUB-WAVELENGTH STRUCTURE WITH POLARIZATION FEATURE FOR LIGHT EMITTING DIODE

2009 ◽  
Vol 16 (04) ◽  
pp. 631-634 ◽  
Author(s):  
CHENG-HAO KO ◽  
JIAN-SHIAN LIN ◽  
CHANG-TAI CHEN ◽  
NIEN-PO CHEN
Keyword(s):  
Light Emitting Diode ◽  
Red Light ◽  
Fdtd Method ◽  
Dielectric Materials ◽  
Transmission Efficiency ◽  
Light Emitting ◽  
Light Region ◽  
Fluorescence Efficiency ◽  
Difference Time ◽  
Sub Wavelength

A two-dimensional sub-wavelength grating (SWG) is fabricated on light-emitting diodes (LEDs). The SWG is simulated by finite-difference time-domain (FDTD) method. The SWG surface has silver-coated dielectric materials with sinusoidal structures, 175 nm period and 125 m depth of groove. When the incident wave is in the red light region of 600–700nm, the transmission efficiency of TM propagated light will reach 0.82. If this SWG structure is applied in LCD direct backlight module, the lower polarization piece can be replaced and fluorescence efficiency of LED can be improved.

Three Dimensional Radiation Feature Calculation for Terahertz Photoconductive Antenna Based on FDTD Method

2014 ◽  
Vol 556-562 ◽  
pp. 1499-1505 ◽  
Author(s):  
Fei Yu Lian ◽  
Guang Feng Jin ◽  
Mai Xia Fu
Keyword(s):  
Fdtd Method ◽  
Three Dimensional ◽  
Photoconductive Antenna ◽  
Actual Application ◽  
Application Condition ◽  
Spectrum Detection ◽  
Radiation Properties ◽  
Difference Time ◽  
Feature Calculation ◽  
Terahertz Generation And Detection

It is photoconductive antenna for terahertz generation and detection to be applied widely as a radiation resource. It has a significant application prospect in many areas such as terahertz imaging, spectrum detection and so on. In this paper, we proposed a 3-D radiation feature calculation method for terahertz photoconductive antenna using Finite Difference Time Domain (FDTD), and elaborated the influence of semiconductor drift current, diffusion current to electromagnetic field based on the radiation principle of photoconductive antenna. According to actual application condition, we simplified drift equation and continuity equation, and obtained the iteration equation of current density, electric field and magnetic field, and at last, we illustrated a calculation flow of radiation properties of photoconductive antenna.

An Error-Reduced ADI-FDTD Algorithm in Debye Media

2013 ◽  
Vol 765-767 ◽  
pp. 567-571
Author(s):  
Hui Fu ◽  
Chuan Wen Zhu ◽  
Gang Guo ◽  
Quan Min Wang
Keyword(s):  
Large Time ◽  
Fdtd Method ◽  
Three Dimensional ◽  
Alternating Direction Implicit ◽  
Truncation Errors ◽  
Computation Efficiency ◽  
Alternating Direction ◽  
Implicit Finite Difference ◽  
Fdtd Methods ◽  
Difference Time

The alternating direction implicit finite-difference time-domain (ADI-FDTD) method is an unconditionally stable numerical scheme, being proposed to remove stability limitations in conventional FDTD methods. Though the computation efficiency has been improved by ADI-FDTD, significant errors have been observed at large time steps. By compensating truncation errors, a low error ADI-FDTD method in Debye media is proposed based the ER(error reduced)-ADI-FDTD, complete three dimensional equations are derived. Simulation results are anlalyzed and compared with existing methods.

IMPLEMENTATION OF THE LORENTZ–DRUDE MODEL INCORPORATED FDTD METHOD ON MULTIPLE GPUs FOR PLASMONICS APPLICATIONS

2014 ◽  
Vol 11 (04) ◽  
pp. 1350063 ◽  
Author(s):  
IFTIKHAR AHMED ◽  
RICK SIOW MONG GOH ◽  
ENG HUAT KHOO ◽  
KIM HUAT LEE ◽  
SIAW KIAN ZHONG ◽  
...  
Keyword(s):  
Time Domain ◽  
Graphics Processing Units ◽  
Maxwell Equations ◽  
Fdtd Method ◽  
Three Dimensional ◽  
Drude Model ◽  
Multiple Gpus ◽  
Device Architecture ◽  
Graphics Processing ◽  
Difference Time

The Lorentz–Drude model incorporated Maxwell equations are simulated by using the three-dimensional finite difference time domain (FDTD) method and the method is parallelized on multiple graphics processing units (GPUs) for plasmonics applications. The compute unified device architecture (CUDA) is used for GPU parallelization. The Lorentz–Drude (LD) model is used to simulate the dispersive nature of materials in plasmonics domain and the auxiliary differential equation (ADE) approach is used to make it consistent with time domain Maxwell equations. Different aspects of multiple GPUs for the FDTD method are presented such as comparison of different numbers of GPUs, transfer time in between them, synchronous, and asynchronous passing. It is shown that by using multiple GPUs in parallel fashion, significant reduction in the simulation time can be achieved as compared to the single GPU.

The Theoretical Study of TM Transmittance and Contrast Ratio for Sub-Wavelength Metallic Gratings

2014 ◽  
Vol 575 ◽  
pp. 138-141
Author(s):  
Ren Cheng Jin ◽  
Yang Rui ◽  
Jin Kui Chu ◽  
Ying Jie Zhang
Keyword(s):  
Performance Indicators ◽  
Theoretical Study ◽  
Structural Parameters ◽  
Contrast Ratio ◽  
Fdtd Method ◽  
Slit Width ◽  
Wave Band ◽  
Metallic Gratings ◽  
Difference Time ◽  
Sub Wavelength

According to the requirement of the bionic navigation sensitive wave band of 380nm~520nm for sub-wavelength metallic gratings, in order to achieve performance indicators under the basic structural parameters. Analyzing TM transmittance and contrast ratio is carried out by employing finite-difference time-domain (FDTD) method. The result reveals that height, slit width and dielectric of grating impact TM transmittance and contrast ratio in various extents, and the greatest influence on the TM transmittance and contrast ratio is slit dielectric and slit width respectively.

scholarly journals Possible warming effect of fine particulate matter in the atmosphere

2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Shau-Liang Chen ◽  
Sih-Wei Chang ◽  
Yen-Jen Chen ◽  
Hsuen-Li Chen
Keyword(s):  
Particulate Matter ◽  
Fine Particles ◽  
Fine Particulate Matter ◽  
Three Dimensional ◽  
Mie Scattering ◽  
Dust Particles ◽  
Long Wavelength ◽  
Inorganic Aerosols ◽  
Fine Particulate ◽  
Difference Time

AbstractParticulate matter emitted through human activities not only pollutes the air, but also cools the Earth by scattering shortwave solar radiation. However, coarser dust particles have been found to exert a warming effect that could, to some extent compensate for the cooling effect of fine dust. Here we investigate the radiative effects of sulfate containing aerosols of various sizes and core/shell structures using Mie scattering and three-dimensional finite difference time domain simulations of the electromagnetic fields inside and around particulate matter particles. We find that not only coarse dust, but also fine non-light-absorbing inorganic aerosols such as sulfate can have a warming effect. Specifically, although the opacity of fine particles decreases at longer wavelengths, they can strongly absorb and re-emit thermal radiation under resonance conditions at long wavelength. We suggest that these effects need to be taken into account when assessing the contribution of aerosols to climate change.

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