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.

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 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

Mid-infrared high birefringence As2Se3-based PCF with large nonlinearity and distinctive dispersion by using asymmetric elliptical air hole cladding

2018 ◽  
Vol 32 (03) ◽  
pp. 1850023 ◽  
Author(s):  
Zhanqiang Hui ◽  
Min Yang ◽  
Youkun Zhang ◽  
Meizhi Zhang
Keyword(s):  
Hexagonal Lattice ◽  
Fdtd Method ◽  
Polarization Mode Dispersion ◽  
Infrared Range ◽  
Polarization Direction ◽  
Mid Infrared ◽  
High Birefringence ◽  
Crystal Fiber ◽  
Mode Dispersion ◽  
Difference Time

A novel high birefringence As2Se3-based hexagonal lattice photonic crystal fiber (PCF) is proposed. In the structure, a central defect core and three kinds of elliptical air holes with different major axes length and ellipticity are introduced in the cladding. The finite difference time domain (FDTD) method with perfectly matched layer (PML) absorption boundary conditions are used to simulate the guided modes of the designed PCF. The properties of this PCF are investigated in detail including the birefringence, beat length, dispersion, nonlinearity and polarization mode dispersion in the 2–5 [Formula: see text] mid-infrared range. The results show that for the optimized structure parameters of [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text], the high birefringence of 0.1192 and beat length of 41.93 [Formula: see text] are obtained. The maximum nonlinearity coefficient of 10,050 w[Formula: see text]km[Formula: see text] and 15,200 w[Formula: see text]km[Formula: see text] for x- and y-polarization modes are achieved. The distinctive dispersion is analyzed, which is all-normal in x-polarization direction while it has two zero dispersion points at 3.18 [Formula: see text] and 3.65 [Formula: see text] in y-polarization direction. The designed PCF with high birefringence, large nonlinearity and distinctive dispersion will be beneficial for mid-infrared fiber sensing, mid-infrared spectroscopy and nonlinear optics applications.

2x2 Optical Switch Based on Silicon-on-Insulator Microring Resonator

2011 ◽  
Vol 378-379 ◽  
pp. 531-534
Author(s):  
B. Mardiana ◽  
Hanim Abdul Razak ◽  
H. Hazura ◽  
S. Shaari ◽  
P. Susthitha Menon ◽  
...  
Keyword(s):  
Optical Switch ◽  
Free Spectral Range ◽  
Fdtd Method ◽  
Single Mode ◽  
Microring Resonator ◽  
Silicon On Insulator ◽  
Electric Signal ◽  
Compact Size ◽  
Near Future ◽  
Difference Time

In near future, silicon-on-insulator (SOI) microring resonator are expected to be basic components for wavelength filtering and switching due to their compact size and wide free spectral range (FSR). In this paper, a 2X2 optical switch by using active microring resonator is proposed. The switch is consists of second order serially cascaded microring coupled to a pair of waveguide. The ON/OFF state of the design is control by electric signal which will vary the refractive index. The device is design to operate at 1.55µm wavelength. With a 500nm x 200nm rib dimensions, the design is proven to have single mode behaviour. Finite-Difference Time-Domain (FDTD) method simulation by RSOFT software is use to characterize the device performance. The results show that the 2X2 optical switch proposed can be an efficient device to be functioning in WDM application.

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

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.

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.

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