Angled: LNOI
Highlighted features: angle etch, mask etch, expand window with lower resolution, overlap integral.
This code example is licensed under the BSD 3-Clause License.
import emodeconnection as emc
## Set simulation parameters
wavelength = 1550 # [nm] wavelength
dx, dy = 10, 10 # [nm] resolution
w_core = 1000 # [nm] waveguide core width
w_trench = 1000 # [nm] waveguide side trench width
h_core = 500 # [nm] waveguide core height
h_clad = 1000 # [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 = '0S' # boundary condition
## Connect and initialize EMode
em = emc.EMode()
## View material database
em.material_explorer()
## 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 = 'Air',
boundary_condition = boundary,
expansion_resolution = 20, expansion_size = 1500)
## Draw shapes
em.shape(name = 'BOX', refractive_index = 'SiO2', height = h_clad)
em.shape(name = 'core', refractive_index = 'LN_MgO_z', height = h_core,
etch_depth = h_core*3/4, mask = w_core, sidewall_angle = 15)
## Solve the first mode
em.FDM()
em.confinement(shape_list = 'core')
em.report()
em.label(label = '0') # save the data from the first mode
## Solve the second mode
em.shape(name = 'core', mask = w_core + 100)
em.FDM()
em.confinement(shape_list = 'core')
em.report()
## Calculate the overlap integral
em.overlap(label_a = '0', mode_a = 0, mode_b = 0)
overlap = em.get('overlap')
print('Power overlap: %0.3f %%' % (overlap*100))
## Plot the field and refractive index profiles
em.plot(window_display = True)
## Get the refractive index of the core
res = em.refractive_index(material = 'LN_MgO_z', wavelength = wavelength, reference = True)
n_LN, ref = res
print('\nRefractive index of LN:', n_LN)
print(ref)
## Close EMode
em.close()
% Set simulation parameters
wavelength = 1550; % [nm] wavelength
dx = 10; dy = 10; % [nm] resolution
w_core = 1000; % [nm] waveguide core width
w_trench = 1000; % [nm] waveguide side trench width
h_core = 500; % [nm] waveguide core height
h_clad = 1000; % [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 = '0S'; % boundary condition
% Connect and initialize EMode
em = emodeconnection();
% View material database
em.material_explorer();
% 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', 'Air', ...
'boundary_condition', boundary, ...
'expansion_resolution', 20, 'expansion_size', 1500);
% Draw shapes
em.shape('name', 'BOX', 'refractive_index', 'SiO2', 'height', h_clad);
em.shape('name', 'core', 'refractive_index', 'LN_MgO_z', 'height', h_core, ...
'etch_depth', h_core*3/4, 'mask', w_core, 'sidewall_angle', 15);
% Solve the first mode
em.FDM();
em.confinement('shape_list', 'core');
em.report();
em.label(label = '0'); % save the data from the first mode
% Solve the second mode
em.shape('name', 'core', 'mask', w_core + 100);
em.FDM();
em.confinement('shape_list', 'core');
em.report();
% Calculate the overlap integral
em.overlap('label_a', '0', 'mode_a', 0, 'mode_b', 0);
overlap = em.get('overlap');
fprintf('Power overlap: %0.3f %%', (overlap*100));
% Plot the field and refractive index profiles
em.plot('window_display', true);
% Get the refractive index of the core
res = em.refractive_index('material', 'LN_MgO_z', 'wavelength', wavelength, 'reference', true);
n_LN = res{1};
ref = res{2};
fprintf('\nRefractive index of LN: [%0.6f, %0.6f, %0.6f]\n', n_LN);
if (find(ref=='%'))
ref = [ref(1:find(ref=='%')-1) '%' ref(find(ref=='%'):end)];
end
fprintf([ref '\n']);
% Close EMode
em.close();
Console output:
EMode 0.1.1 - email
Meshing... completed in 0.3 sec
Solving... completed in 1.7 sec
Wavelength: 1550.0 nm
Mode # n_eff TE % Loss (dB/m) core confinement
-------- -------- ------ ------------- ------------------
TE-0 1.772699 98.8 % 0.000 82.1 %
Meshing... completed in 0.3 sec
Solving... completed in 1.7 sec
Wavelength: 1550.0 nm
Mode # n_eff TE % Loss (dB/m) core confinement
-------- -------- ------ ------------- ------------------
TE-0 1.794352 99.1 % 0.000 83.3 %
Exited EMode
Power overlap: 98.628 %
Refractive index of LN: [2.1305703312029918, 2.208812688703256, 2.208812688703256]
O. Gayer, Z. Sacks, E. Galun, and A. Arie, "Temperature and wavelength dependent refractive index equations for MgO-doped congruent and stoichiometric LiNbO3," Appl. Phys.B 91, 343 (2008).
Notes: z-cut congruent lithium niobate, 5 % MgO-doped. Temperature is 24.5 C. The n_e is the x-direction and n_o is the y- and z-direction.
Wavelength range: 500 nm to 4000 nm
Figures:
