{"id":367183,"date":"2024-05-16T15:12:25","date_gmt":"2024-05-16T15:12:25","guid":{"rendered":"\/forum\/forums\/topic\/nonlinear-optical-material-design\/"},"modified":"2024-05-16T15:12:25","modified_gmt":"2024-05-16T15:12:25","slug":"nonlinear-optical-material-design","status":"closed","type":"topic","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/nonlinear-optical-material-design\/","title":{"rendered":"Nonlinear optical material design"},"content":{"rendered":"

Hello,<\/p>\n

I want to design one material which permitivity(as a function of frequency) as well as ch2 property (not diagonal d33,d21,d22,d15 which depends on frequency) in lumerical FDTD( iam using 2024R2)  all data i want to give in one material how i will give? and i could not able to import material  data set also.<\/p>\n

Here i wrote in MATLAB code, which i want to design..<\/p>\n

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 <\/div>\n
<\/div>\n
<\/div>\n
% Define Frequency range in THz<\/span><\/div>\n
f1 = linspace(0, 10, 500)* (10^12); % in THz<\/span><\/div>\n
w = 2 * pi * f1;<\/div>\n
% Lorentz parameters (infrared and optical frequencies)<\/span><\/div>\n
omegap_e = [248 274 307 628 692] * 3 * 10^10; % phonon resonant frequency for e axis<\/span><\/div>\n
omegap_o = [152 236 265 322 363 431 586 670] * 3 * 10^10; % phonon resonant frequency for o axis<\/span><\/div>\n
S_e = [16 1 0.16 2.55 0.34]; % oscilator strength for e-axis<\/span><\/div>\n
S_o = [22 0.8 5.5 2.2 2.3 0.18 3.3 0.2];% oscilator strength for o-axis<\/span><\/div>\n
Gamma_e = [21 14 25 34 49] * 3 * 10^10; % phonon damping rate for e-axis<\/span><\/div>\n
Gamma_o = [14 12 12 11 33 12 35 47] * 3 * 10^10; % phonon damping rate for o-axis<\/span><\/div>\n
epsilon_p_e = 4.6; % high frefency permitivity limit for e axis<\/span><\/div>\n
epsilon_p_o = 5.0; % high frefency permitivity limit for o axis<\/span><\/div>\n
epsilon_Le = epsilon_p_e * ones(size(w)); % Initialize epsilon_L for e axis<\/span><\/div>\n
epsilon_Lo = epsilon_p_o * ones(size(w)); % Initialize epsilon_L for o axis<\/span><\/div>\n
<\/div>\n
% Lorentzian contributions for e axis<\/span><\/div>\n
for k1 = 1:length(omegap_e)<\/div>\n
epsilon_Le = epsilon_Le + (S_e(k1) * omegap_e(k1)^2) .\/ ((omegap_e(k1)^2 – w.^2) – 1i * Gamma_e(k1) * w);<\/div>\n
end<\/div>\n
refractive_index_e=sqrt(epsilon_Le);<\/div>\n
n_e=refractive_index_e;<\/div>\n
E_er=real(epsilon_Le);<\/div>\n
E_ei=imag(epsilon_Le);<\/div>\n
 <\/div>\n
% Lorentzian contributions for o axis<\/span><\/div>\n
for k2 = 1:length(omegap_o)<\/div>\n
epsilon_Lo = epsilon_Lo + (S_o(k2) * omegap_o(k2)^2) .\/ ((omegap_o(k2)^2 – w.^2) – 1i * Gamma_o(k2) * w);<\/div>\n
end<\/div>\n
refractive_index_o=sqrt(epsilon_Lo);<\/div>\n
n_o=(refractive_index_o);<\/div>\n
E_or=real(epsilon_Lo);<\/div>\n
E_oi=imag(epsilon_Lo);<\/div>\n
% linear microwave susceptibility<\/span><\/div>\n
chi_e=n_e.^2-1;%% electronic contribution for e axis<\/span><\/div>\n
chi_o=n_o.^2-1;%% electronic contribution for o axis<\/span><\/div>\n
chi_ion_e=epsilon_Le-n_e.^2-1;% ionic contribution for e axis<\/span><\/div>\n
chi_ion_o=(epsilon_Lo)-(n_o).^2-1;% ionic contribution for e axis<\/span><\/div>\n
<\/div>\n
% Define constants for electronic and ionic parts<\/span><\/div>\n
delta_333_e = 0.6*10^-12;<\/div>\n
delta_222_e = 0.064*10^-12; <\/div>\n
delta_311_e =0.18*10^-12; <\/div>\n
delta_113_e = 0.31*10^-12; <\/div>\n
<\/div>\n
delta_333_ion =0.304* 10^-12;<\/div>\n
delta_222_ion =0.0369* 10^-12; <\/div>\n
delta_311_ion =0.167*10^-12; <\/div>\n
delta_113_ion =0.41* 10^-12; <\/div>\n
<\/div>\n
chi_1e=3.884;<\/div>\n
chi_3e=3.544;<\/div>\n
<\/div>\n
<\/div>\n
% Calculate Nonlinear coefficient components<\/span><\/div>\n
d33 = abs(delta_333_e * chi_e .* chi_3e .* chi_3e + delta_333_ion * chi_3e.* chi_3e .* chi_ion_e);<\/div>\n
d31 = abs(delta_311_e * chi_e .* chi_1e .* chi_1e + delta_311_ion * chi_1e .* chi_1e .* chi_ion_e);<\/div>\n
d15 = abs(delta_113_e * chi_o .* chi_1e .* chi_1e + delta_113_ion * chi_1e .* chi_1e .* chi_ion_o);<\/div>\n
%d15 = d31+(delta_113_e * chi_o.* chi_1e.*chi_3e + delta_113_ion * chi_3e .* chi_1e.* chi_ion_o);<\/div>\n
d22 = abs(delta_222_e * chi_o .* chi_3e .* chi_3e + delta_222_ion * chi_3e .* chi_3e .* chi_ion_o);<\/div>\n
<\/div>\n
<\/div>\n
<\/div>\n
figure;<\/div>\n
plot(w, d33, ‘r’, w, d31, ‘b’, w, d15, ‘m’, w, d22, ‘k’);<\/div>\n
legend(‘d_{33}’, ‘d_{31}’, ‘d_{15}’, ‘d_{22}’);<\/div>\n
xlabel(‘Frequency(Hz)’);<\/div>\n
ylabel(‘Nonlinear Coefficient(pm\/V)’);<\/div>\n
title(‘Nonlinear coefficient’);<\/div>\n
grid on;<\/div>\n
% Plot w vs permitivity (real part)for e and o axis<\/div>\n
figure;<\/div>\n
plot(w, real(epsilon_Le), ‘r’, w, real(epsilon_Lo), ‘b’);<\/div>\n
legend(‘e-axis’, ‘o-axis’)<\/div>\n
xlabel(‘Frequency (Hz)’);<\/div>\n
ylabel(‘Re(\\epsilon)’);<\/div>\n
title(‘Real Permitivity’);<\/div>\n
% Plot w vs imaginary part of permitivity for e and o axis<\/div>\n
figure;<\/div>\n
plot(w, imag(epsilon_Le), ‘r’, w, imag(epsilon_Lo), ‘b’);<\/div>\n
xlabel(‘Frequency (Hz)’);<\/div>\n
legend(‘e-axis’, ‘o-axis’)<\/div>\n
ylabel(‘Im(\\epsilon)’);<\/div>\n
title(‘Imaginary permitivity’);<\/div>\n
 <\/div>\n
please let me know .<\/div>\n
Thank you.<\/div>\n
<\/div>\n<\/div>\n","protected":false},"template":"","class_list":["post-367183","topic","type-topic","status-closed","hentry"],"aioseo_notices":[],"aioseo_head":"\n\t\t\n\t\n\t\n\t\n\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t