Dielectric Cylinder 2D
中文/English
Dielectric cylinder 2D TM (Ex Ez Hy)
Dielectric cylinder 2D TM (Ex Ez Hy)
The FonSinEM simulation results V.S. Analytical solution
The FonSinEM simulation results V.S. Analytical solution
2D (TM) dielectric cylinder(Y-axis infinity) - To simulate the scattering-absorption spectrum in optical range
2D (TM) dielectric cylinder(Y-axis infinity) - To simulate the scattering-absorption spectrum in optical range
The radius of cylinder is 200 nm (diameter = 400 nm), and the refractive index n=1.5. permittivity = n^2=2.25
The radius of cylinder is 200 nm (diameter = 400 nm), and the refractive index n=1.5. permittivity = n^2=2.25
Add the boundary of the CAD files (FreeCAD)
Add the boundary of the CAD files (FreeCAD)
Reference : 3D-CAD Simulation & Examples
Reference : 3D-CAD Simulation & Examples
Due to FreeCAD default unit is mm, and in this case the sphere unit is nm. If use nm unit in FreeCAD, the resolution of output STL file will not enough. So, at here express
Due to FreeCAD default unit is mm, and in this case the sphere unit is nm. If use nm unit in FreeCAD, the resolution of output STL file will not enough. So, at here express
"the unit can directly transform between any unit, nm <=> um <=> mm "
"the unit can directly transform between any unit, nm <=> um <=> mm "
FreeCAD:
FreeCAD:
diameter of cylinder: 0.4 mm = 400 um
diameter of cylinder: 0.4 mm = 400 um
length of the boundary: 1 mm = 1000 um
length of the boundary: 1 mm = 1000 um
Define Parameters
Define Parameters
1. Selected the simulation dimension.
1. Selected the simulation dimension.
2. Define total x, y, z length that equal to CAD, and then set a appropriate resolution.
2. Define total x, y, z length that equal to CAD, and then set a appropriate resolution.
3. Import CAD files.
3. Import CAD files.
4. Define the material of each CAD.
4. Define the material of each CAD.
5. Press【建立網格 Cad to Grids (Create)】button to create simulation grids.
5. Press【建立網格 Cad to Grids (Create)】button to create simulation grids.
* Dielectric Constant of cylinder define n^2 = 1.5^2 = 2.25,
* Dielectric Constant of cylinder define n^2 = 1.5^2 = 2.25,
(FreeCAD : um ==> FonSinEM : nm )
(FreeCAD : um ==> FonSinEM : nm )
FreeCAD
FreeCAD
diameter of cylinder: 0.4 mm = 400 um
diameter of cylinder: 0.4 mm = 400 um
length of the boundary: 1 mm = 1000 um
length of the boundary: 1 mm = 1000 um
FonSinEM
FonSinEM
Attention! the X, Z length define 1000, unit is nm
Attention! the X, Z length define 1000, unit is nm
and the cylinder will be 400 nm in FonSinEM
and the cylinder will be 400 nm in FonSinEM
"the unit can directly transform between any unit, nm <=> um <=> mm "
"the unit can directly transform between any unit, nm <=> um <=> mm "
A. Define the boundary conditions
A. Define the boundary conditions
B. Press the【創建 (Create)】button => Create the total grid size (Include the boundary condition & add space)
B. Press the【創建 (Create)】button => Create the total grid size (Include the boundary condition & add space)
To simulate the Scattering-Absorption spectrum, select the (TFSF-RCS) radar cross section source
To simulate the Scattering-Absorption spectrum, select the (TFSF-RCS) radar cross section source
Checked out the simulation geometries, and then press 【輸出 Output】button to output the geometries files
Checked out the simulation geometries, and then press 【輸出 Output】button to output the geometries files
Data_Materials.csv // (simulation index of structures)
Data_Materials.csv // (simulation index of structures)
Comparison of FonSinEM simulation results and analytical solution
Comparison of FonSinEM simulation results and analytical solution
Mie theory software
MieLab:
A Software Tool to Perform Calculations on the Scattering of Electromagnetic Waves by Multilayered Spheres
http://www.hindawi.com/journals/ijs/2011/583743/
Nmie:
https://nanohub.org/resources/8228
http://juluribk.com/2010/05/11/nmie-extinction-scattering-and-absorption-efficiencies-of-multilayer-nanoparticles/
This website contains many freeware,FDTD、FEM、Ray tracing method and mie theory codes
http://www.scattport.org/diogenes.iwt.uni-bremen.de/vt/scattport/index.php/light-scattering-software/mie-type-codes.html
====== Far-Field Diffraction Pattern Analysis=====
====== Far-Field Diffraction Pattern Analysis=====
The near to far field transformation (NTFF) is a technology that to integrate the near field EM wave to the far-field diffraction pattern in FDTD algorithm. In FonSinEM, can use the "Pulse" and "Continue Wave (CW)" to do this. The difference between these is
The near to far field transformation (NTFF) is a technology that to integrate the near field EM wave to the far-field diffraction pattern in FDTD algorithm. In FonSinEM, can use the "Pulse" and "Continue Wave (CW)" to do this. The difference between these is
In Pulse source, the observation range are fixed, but can obtain multi frequencies far field pattern at once calculation.
In Pulse source, the observation range are fixed, but can obtain multi frequencies far field pattern at once calculation.
Menu ==> 【其它 Other】==>【遠場Far-Field】
In CW source, the frequency is fixed, but can change observation range arbitrary.
In CW source, the frequency is fixed, but can change observation range arbitrary.
Use the steady state filed pattern analysis
following are the detail of these two NTFF method.
================== (Pulse) ================
================== (Pulse) ================
1. Checked "Pulse" wave
1. Checked "Pulse" wave
2. Checked ☑近場觀測輸出 (Output NearField Ob.)-脈波 (Pulse Only)
2. Checked ☑近場觀測輸出 (Output NearField Ob.)-脈波 (Pulse Only)
The observation range will be defined automatically if the incident source type is TFSF-RCS.
The observation range will be defined automatically if the incident source type is TFSF-RCS.
after calculation finished, will output
after calculation finished, will output
Pulse_DFT_1_p1.csv
Pulse_DFT_1_p1.csv
Pulse_DFT_2_p1.csv
Pulse_DFT_2_p1.csv
these two files, these are the EM data of the near field simulation.
these two files, these are the EM data of the near field simulation.
3. Menu : 其他(Other) ==> 遠場 (Far Field)
3. Menu : 其他(Other) ==> 遠場 (Far Field)
Source type : TFSF-RCS*
Source type : Others
Output the far-field values of the FonSinEM simulation
Output the far-field values of the FonSinEM simulation
use the following code
use the following code
csvwrite('scan_theta.csv',scan_theta)
csvwrite('RCS_theta.csv',RCS_theta)
csvwrite('RCS_phi.csv',RCS_phi)
The analytical solution code
The analytical solution code
MatScat
Author :Jan Schäfer
http://www.mathworks.com/matlabcentral/fileexchange/36831-matscat
scan_theta=csvread('scan_theta.csv');
RCS_theta=csvread('RCS_theta.csv');
RCS_phi=csvread('RCS_phi.csv');
%% Define test parameters
lambda0=400e-9;
dia = 400e-9; % cylinder diameter
ns = 1.5 + 0.j; % cylinder refractive index (complex) epsr=ns^2
nm = 1; % outer medium refractive index (real)
nang = 180; % number of far field angles to evaluate
zeta = 90; % cylinder inclination angle (90 deg = perpendicular)
[T, C, ang] = calccyl(dia/2., ns, nm, lambda0, nang, zeta);
fctr = 2/pi/C.k;
Far2E= fctr*squeeze(abs(T(2,2,:).^2)); % 2E
figure(1);hold on;
plot(scan_theta,RCS_theta(172,:),'r','Linewidth',3);
plot(ang, Far2E/max(Far2E(:))*max(RCS_theta(172,:)),'*b');
xlabel('Scattering Angle');
title('TM(ExEzHy)')
legend('FDTD','Analytical Solution')
Comparison of FonSinEM and Analytical solution
Comparison of FonSinEM and Analytical solution
================== (CW) ================
================== (CW) ================
Here choice the wavelength (lambda)=400 nm source of CW wave
Here choice the wavelength (lambda)=400 nm source of CW wave
Steady state field pattern analysis
Steady state field pattern analysis
Setup the observation range and then press the (NTFF Transformation) button
Setup the observation range and then press the (NTFF Transformation) button
observation range : x=19,213, z=19,213 . In field pattern analysis, can change the observation range arbitrary
observation range : x=19,213, z=19,213 . In field pattern analysis, can change the observation range arbitrary
Output the far-field values of the FonSinEM simulation
Output the far-field values of the FonSinEM simulation
use the following code
use the following code
a(:,1)=scan_theta';
a(:,2)=RCS_theta';
a(:,3)=RCS_phi';
csvwrite('Far2DTM.csv',a)
The analytical solution code
The analytical solution code
MatScat
Author :Jan Schäfer
http://www.mathworks.com/matlabcentral/fileexchange/36831-matscat
load Far2DTM.csv
scan_theta=Far2DTM(:,1);
RCS_theta=Far2DTM(:,2);
RCS_phi=Far2DTM(:,3);
lambda0=400e-9;
%% Define test parameters
dia = 400e-9; % cylinder diameter
ns = 1.5 + 0.j; % cylinder refractive index (complex) epsr=ns^2
nm = 1; % outer medium refractive index (real)
nang = 180; % number of far field angles to evaluate
zeta = 90; % cylinder inclination angle (90 deg = perpendicular)
[T, C, ang] = calccyl(dia/2., ns, nm, lambda0, nang, zeta);
fctr = 2/pi/C.k;
Far2E= fctr*squeeze(abs(T(2,2,:).^2)); % 2E
figure(1);hold on;
plot(scan_theta,RCS_theta,'r','Linewidth',3);
plot(ang, Far2E/max(Far2E(:))*max(RCS_theta(:)),'*b');
xlabel('Scattering Angle');
title('TM(ExEzHy)')
legend('FDTD','Analytical Solution')
Comparison of FonSinEM and Analytical solution
Comparison of FonSinEM and Analytical solution
Mie theory software
MieLab:
A Software Tool to Perform Calculations on the Scattering of Electromagnetic Waves by Multilayered Spheres
http://www.hindawi.com/journals/ijs/2011/583743/
Nmie:
https://nanohub.org/resources/8228
http://juluribk.com/2010/05/11/nmie-extinction-scattering-and-absorption-efficiencies-of-multilayer-nanoparticles/
This website contains many freeware,FDTD、FEM、Ray tracing method and mie theory codes
http://www.scattport.org/diogenes.iwt.uni-bremen.de/vt/scattport/index.php/light-scattering-software/mie-type-codes.html