Bending: SiN

Highlighted features: bend radius, pml layers, confinement factor, saving plots.

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

  • Python
  • MATLAB
import emodeconnection as emc

## Set simulation parameters
wavelength = 980 # [nm] wavelength
dx, dy = 10, 10 # [nm] resolution
w_core = 2000 # [nm] waveguide core width
w_trench = 2250 # [nm] waveguide side trench width
h_core = 200 # [nm] waveguide core height
h_clad = 2250 # [nm] waveguide top and bottom clad
window_width = w_core + w_trench*2 # [nm]
window_height = h_core + h_clad*2 # [nm]
num_modes = 1 # [-] number of modes
boundary = 'TE' # boundary condition

bend_radius = 100e3 # [nm] bend radius
x_off = 500 # [nm] waveguide x-offset for applying the bend radius at the center of the waveguide core rather than the center of the window

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

## Add custom material
equation = '(1 + 0.6961663/(1 - (0.0684043/x)^2) + 0.4079426/(1 - (0.1162414/x)^2) + 0.8974794/(1 - (9.896161/x)^2))^0.5'
em.add_material(name = 'custom_SiO2',
    refractive_index_equation = equation, wavelength_unit = 'um')

## Settings
em.settings(
    wavelength = wavelength, x_resolution = dx, y_resolution = dy,
    window_width = window_width, window_height = window_height,
    num_modes = num_modes, background_refractive_index = 'custom_SiO2',
    boundary_condition = boundary, bend_radius = bend_radius + x_off,
    pml_NSEW_bool = [0,0,1,1], num_pml_layers = 20,
    max_effective_index = 1.7)

## Draw shapes
em.shape(
    name = 'core', refractive_index = 'SiN', width = w_core, height = h_core, position = [-x_off, window_height/2])

## Launch FDM solver
em.FDM()

## Display the effective indices, loss, and core confinement
em.confinement()
em.report()

## Save the field and refractive index profiles plots
em.plot(component = 'Ex', file_name = 'field_plot', file_type = 'png')
em.plot(component = 'Index', file_name = 'index_plot', file_type = 'png')

## Plot the field and refractive index profiles
em.plot()

## Collect all variable names and close EMode
variables = em.inspect()
em.close()
% Set simulation parameters
wavelength = 980; % [nm] wavelength
dx = 10; dy = 10; % [nm] resolution
w_core = 2000; % [nm] waveguide core width
w_trench = 2250; % [nm] waveguide side trench width
x_off = 500; % [nm] waveguide x-offset
h_core = 200; % [nm] waveguide core height
h_clad = 2250; % [nm] waveguide top and bottom clad
window_width = w_core + w_trench*2; % [nm]
window_height = h_core + h_clad*2; % [nm]
num_modes = 1; % [-] number of modes
boundary = 'TE'; % boundary condition
bend_radius = 100e3; % [nm] bend radius

% Connect and initialize EMode
em = emodeconnection();

% Add custom material
equation = '(1 + 0.6961663/(1 - (0.0684043/x)^2) + 0.4079426/(1 - (0.1162414/x)^2) + 0.8974794/(1 - (9.896161/x)^2))^0.5';
em.add_material('name', 'custom_SiO2', ...
    'refractive_index_equation', equation, 'wavelength_unit', 'um');

% Settings
em.settings( ...
    'wavelength', wavelength, 'x_resolution', dx, 'y_resolution', dy, ...
    'window_width', window_width, 'window_height', window_height, ...
    'num_modes', num_modes, 'background_refractive_index', 'custom_SiO2', ...
    'boundary_condition', boundary, 'bend_radius', bend_radius + x_off, ...
    'pml_NSEW_bool', [0,0,1,1], 'num_pml_layers', 20, ...
    'max_effective_index', 1.7);

% Draw shapes
em.shape( ...
    'name', 'core', 'refractive_index', 'SiN', 'width', w_core, 'height', h_core, 'position', [-x_off, window_height/2]);

% Launch FDM solver
em.FDM();

% Display the effective indices, loss, and core confinement
em.confinement();
em.report();

% Plot the field and refractive index profiles
em.plot('component', 'Ex', 'file_name', 'field_plot', 'file_type', 'png');
em.plot('component', 'Index', 'file_name', 'index_plot', 'file_type', 'png');

% Plot the field and refractive index profiles
em.plot();

% Collect all variable names and close EMode
variables = em.inspect();
em.close();

Console output:

EMode 0.1.1 - email
Meshing... completed in 0.2 sec
Solving... completed in 3.4 sec

Wavelength: 980.0 nm

  Mode #     n_eff     TE %    Loss (dB/m)    core confinement
--------  --------  -------  -------------  ------------------
    TE-0  1.692391  100.0 %          0.000              62.0 %

Exited EMode

Figures:

../_images/field_plot.png
../_images/index_plot1.png