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.

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

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.

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 Defects-Induced Hot Spots in TATB

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Zhonghua Yan ◽  
Chuanchao Zhang ◽  
Hongwei Yan ◽  
Zhijie Li ◽  
Li Li ◽  
...  
Keyword(s):  
Hot Spots ◽  
Energetic Materials ◽  
Finite Difference Time Domain ◽  
Fdtd Method ◽  
Three Dimensional ◽  
Laser Ignition ◽  
Ignition Process ◽  
Incident Laser ◽  
Three Dimensional Models ◽  
Difference Time

We investigate the interaction between the laser and energetic materials with different defects. The three-dimensional models of triaminotrinitrobenzene (TATB) explosives containing spherical pores, craters, and cracks are established, respectively. The laser ignition process of TATB is simulated with three-dimensional finite difference time domain (3D-FDTD) method to study the electromagnetic field distribution surrounding these defects with 355 nm laser incidence. It indicates that the larger defects in the TATB energetic materials have the stronger electric field modulations to initial incident laser for all the three defects, which is easier to lead to the generation of hot spots. Furthermore, TATB materials with spherical pore defects and crater defects are easier to form hot spots than those with narrow crack defects.

FDTD Study of the Surface Waves Detection in Apertureless Scanning Near-Field Microscopy

2008 ◽  
Author(s):  
G. Parent ◽  
S. Fumeron ◽  
D. Lacroix
Keyword(s):  
Surface Waves ◽  
Near Field ◽  
Fdtd Method ◽  
Three Dimensional ◽  
Far Field ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Experimental Tool ◽  
Field Transformation ◽  
Difference Time

Recent studies have shown the importance of surface waves in heat transfer near interfaces. The scanning near field optical microscopy (SNOM) provides an experimental tool to investigate the thermal electromagnetic field near surfaces. In this work, we present a three dimensional model of SNOM devices. This model is based on the finite-difference-time domain (FDTD) method associated to a near to far field transformation. Near field and far field scattered by a silicon tetrahedral tip and by a pecfectly conducting one are presented and discussed.

The CPML for Hybrid Implicit-Explicit FDTD Method Based on Auxiliary Differential Equation

2014 ◽  
Vol 989-994 ◽  
pp. 1869-1872 ◽  
Author(s):  
Yun Fei Mao ◽  
Pu Hua Huang ◽  
Li Guo Ma
Keyword(s):  
Differential Equation ◽  
Time Domain ◽  
Finite Difference Time Domain ◽  
Fdtd Method ◽  
Three Dimensional ◽  
Complex Frequency ◽  
Numerical Examples ◽  
First Order ◽  
Contour Plots ◽  
Difference Time

In this paper, an implementation of the complex-frequency-shifted perfectly matched layer (CPML) is developed for three-dimensional hybrid implicit-explicit (HIE) finite-difference time-domain (FDTD) method based on auxiliary differential equation (ADE). Because of the use of the ADE technique, this method becomes more straightforward and easier to implement. The formulations for the HIE-FDTD CPML are proposed. Numerical examples are given to verify the validity of the presented method. Results show that, both HIE-CPML and FDTD-CPML have almost the same reflection error, while their reflection error is about 30 dB, which is less than HIE Mur’s first-order results. The contour plots indicate that the maximum relative reflection as low as-72 dB is achieved by selecting and .

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