EME: Taper

The simplest EMode example of an EME simulation.

This code example is licensed under the BSD 3-Clause License.

  • Python
  • MATLAB
import emodeconnection as emc

## Set simulation parameters
wavelength = 1550 # [nm] wavelength
dx, dy = 20, 20 # [nm] resolution
h_core = 220 # [nm] waveguide core height
h_clad = 1000 # [nm] waveguide top and bottom clad

window_width = 3400
window_height = h_core + h_clad*2

num_modes = 22 # [-] number of modes
BC = 'TE'

## Connect and initialize EMode
em = emc.EMode(verbose = True)

## Settings
em.settings(
    wavelength = wavelength, x_resolution = dx, y_resolution = dy,
    window_width = window_width, window_height = window_height,
    num_modes = num_modes, boundary_condition = BC,
    background_material = 'SiO2')

## Draw shapes
em.shape(name = 'BOX', material = 'SiO2',
    height = h_clad)
em.shape(name = 'core', material = 'Si',
    height = h_core, etch_depth = h_core*0.90,
    sidewall_angle = 10)

## Launch FDM solver and label profiles
em.shape(name = 'core', mask = 1000)
em.FDM(profile = 'a')
em.report()
em.plot()

em.shape(name = 'core', mask = 2000)
em.FDM(profile = 'b')
em.report()
em.plot()

## Draw EME sections
em.section(profile = 'a', section_type = 'straight',
    length = 2e3)

em.section(section_type = 'taper',
    profile = 'a', profile_end = 'b',
    length = 4000)

em.section(profile = 'b', section_type = 'straight',
    length = 2e3)

## Run EME and plot results
em.EME()
em.plot()
em.plot_S_matrix()

## Close EMode
em.close()
%% Set simulation parameters
wavelength = 1550; % [nm] wavelength
dx = 20; dy = 20; % [nm] resolution
h_core = 220; % [nm] waveguide core height
h_clad = 1000; % [nm] waveguide top and bottom clad

window_width = 3400;
window_height = h_core + h_clad*2;

num_modes = 22; % [-] number of modes
BC = 'TE';

%% Connect and initialize EMode
em = emodeconnection(verbose = true);

%% Settings
em.settings( ...
    wavelength = wavelength, x_resolution = dx, y_resolution = dy, ...
    window_width = window_width, window_height = window_height, ...
    num_modes = num_modes, boundary_condition = BC, ...
    background_material = 'SiO2');

%% Draw shapes
em.shape(name = 'BOX', material = 'SiO2', ...
    height = h_clad);
em.shape(name = 'core', material = 'Si', ...
    height = h_core, etch_depth = h_core*0.90, ...
    sidewall_angle = 10);

%% Launch FDM solver and label profiles
em.shape(name = 'core', mask = 1000);
em.FDM(profile = 'a');
em.report();
em.plot();

em.shape(name = 'core', mask = 2000);
em.FDM(profile = 'b');
em.report();
em.plot();

%% Draw EME sections
em.section(profile = 'a', section_type = 'straight', ...
    length = 2e3);

em.section(section_type = 'taper', ...
    profile = 'a', profile_end = 'b', ...
    length = 4000);

em.section(profile = 'b', section_type = 'straight', ...
    length = 2e3);

%% Run EME and plot results
em.EME();
em.plot();
em.plot_S_matrix();

%% Close EMode
em.close();

Console output:

EMode 0.2.1 - email
Connected on port 63000 to LM-2.
Meshing completed in 0.2 sec
Solving completed in 0.5 sec

Wavelength: 1550.0 nm

  Mode #     n_eff    TE %    Loss (dB/m)
--------  --------  ------  -------------
    TE-0  2.740878  99.8 %          0.000
    TE-1  1.834948  86.3 %          0.000
    TM-2  1.648371  14.6 %          0.000
    TE-3  1.480289  99.8 %          0.000
    TM-4  1.444024   0.0 %          0.000
    TE-5  1.380997  99.0 %          0.000
    TM-6  1.333974   3.8 %          0.000
    TE-7  1.313224  98.9 %          0.000
    TM-8  1.260780   9.1 %          0.000
    TE-9  1.245872  93.8 %          0.000
   TE-10  1.205712  96.3 %          0.000
   TE-11  1.141695  98.8 %          0.000
   TM-12  1.098826   2.3 %          0.000
   TM-13  1.059658   6.2 %          0.000
   TE-14  1.046256  99.4 %          0.000
   TE-15  0.908818  90.9 %          0.000
   TM-16  0.884647  13.2 %          0.000
   TE-17  0.836617  92.4 %          0.000
   TM-18  0.750209  29.3 %          0.000
   TE-19  0.712955  92.6 %          0.000
   TM-20  0.639715  17.8 %          0.000
   TE-21  0.557145  76.4 %          0.000

Meshing completed in 0.2 sec
Solving completed in 0.3 sec

Wavelength: 1550.0 nm

  Mode #     n_eff     TE %    Loss (dB/m)
--------  --------  -------  -------------
    TE-0  2.820614  100.0 %          0.000
    TE-1  2.601685   99.7 %          0.000
    TE-2  2.117344   97.1 %          0.000
    TM-3  1.937158    5.2 %          0.000
    TM-4  1.565193   21.8 %          0.000
    TE-5  1.512582   84.1 %          0.000
    TM-6  1.444024    0.0 %          0.000
    TE-7  1.394522   95.1 %          0.000
    TM-8  1.347977   40.3 %          0.000
    TE-9  1.316026   64.5 %          0.000
   TE-10  1.267170   86.3 %          0.000
   TE-11  1.248576   81.1 %          0.000
   TM-12  1.193778   18.6 %          0.000
   TE-13  1.145446   99.4 %          0.000
   TM-14  1.079657    7.7 %          0.000
   TE-15  1.058558   76.3 %          0.000
   TM-16  1.046977   21.7 %          0.000
   TE-17  0.990949   95.2 %          0.000
   TE-18  0.865006   79.2 %          0.000
   TM-19  0.847538    5.0 %          0.000
   TM-20  0.837589   11.2 %          0.000
   TE-21  0.736539   90.2 %          0.000

Solving S-matrices...
Solving section: 1... Solving completed in 0.3 sec
Meshing completed in 0.2 sec
completed in 0.7 sec
Meshing completed in 0.2 sec
Solving completed in 0.4 sec

Solving section: 2... Solving completed in 0.3 sec
Meshing completed in 0.2 sec
Solving completed in 0.3 sec
Solving completed in 0.3 sec
Solving completed in 0.3 sec
Solving completed in 0.3 sec
Solving completed in 0.3 sec
Solving completed in 0.3 sec
Solving completed in 0.3 sec
Solving completed in 0.3 sec
Solving completed in 0.3 sec
Solving completed in 0.3 sec
Solving completed in 0.3 sec
Solving completed in 0.3 sec
Solving completed in 0.3 sec
Solving completed in 0.3 sec
Solving completed in 0.3 sec
Solving completed in 0.3 sec
completed in 11.4 sec
Meshing completed in 0.2 sec
Solving completed in 0.3 sec

Solving section: 3... Solving completed in 0.3 sec
Meshing completed in 0.2 sec
completed in 0.7 sec
completed in 15.9 sec

Figures:

../_images/Ex_a.png
../_images/Ex_b.png
../_images/Ex_taper.png
../_images/EM_S10_abs2.png