CLEANUP - changes to folder structure
This commit is contained in:
Silas Oettinghaus
219
Theory/Dissertation/mach_zehnder_modulator.m
Normal file
219
Theory/Dissertation/mach_zehnder_modulator.m
Normal file
@@ -0,0 +1,219 @@
|
||||
|
||||
|
||||
% Parameters
|
||||
c0 = physconst('lightspeed'); % [m/s]
|
||||
lambda0 = 1310e-9; % [m]
|
||||
omega0 = 2*pi*c0/lambda0;
|
||||
|
||||
L = 5e-3; % [m] effective phase section length (set as needed)
|
||||
n_eff = 2.2; % [-] effective index (set as needed)
|
||||
|
||||
E0 = 1; % field amplitude (arbitrary)
|
||||
Vpi = 3.2; % [V] half-wave voltage (your V_pi)
|
||||
|
||||
% Drive
|
||||
f0 = 1e9; % [Hz]
|
||||
fs = 200e9; % [Hz]
|
||||
Nper = 2; % number of periods
|
||||
Vpp = 0.6*Vpi; % [V] peak-to-peak of v_drive(t)
|
||||
|
||||
biasV = 1.1; % [V] differential bias added to v_drive
|
||||
|
||||
% Time axis + differential drive voltage v_drive(t)
|
||||
T = Nper/f0;
|
||||
t = (0:1/fs:T-1/fs).';
|
||||
|
||||
|
||||
if 1
|
||||
% SINE
|
||||
v_drive = biasV + (Vpp/2)*sin(2*pi*f0*t); % v_drive(t) (peak = Vpp/2)
|
||||
|
||||
else
|
||||
|
||||
% --- Generate PAM-4 Sequence ---
|
||||
symbols = linspace(-0.5, 0.5, 4);
|
||||
num_symbols = 12; % Increased slightly for better visual
|
||||
rng(44);
|
||||
random_data = symbols(randi(4, 1, num_symbols));
|
||||
|
||||
% Create time axis (Note: T is your period from the sine code)
|
||||
sps = round(T * fs);
|
||||
t = (0:1/fs:(num_symbols*T)-1/fs).';
|
||||
|
||||
% Upsample to rectangular waveform
|
||||
v_pam = repelem(random_data, sps).';
|
||||
|
||||
% Apply swing and bias: Resulting range is [biasV-Vpp/2, biasV+Vpp/2]
|
||||
v_drive_rect = biasV + (v_pam * Vpp);
|
||||
|
||||
% --- Round the edges ---
|
||||
filter_span = round(sps/1.5); % Increased span for smoother "rounding"
|
||||
window = gausswin(filter_span);
|
||||
window = window / sum(window);
|
||||
|
||||
% Apply filter (using 'same' to keep vector length, but be aware of edge transients)
|
||||
v_drive = conv(v_drive_rect, window, 'same');
|
||||
|
||||
end
|
||||
|
||||
|
||||
% Analytic
|
||||
v_ = linspace(-1,2, 2001);
|
||||
% Field transfer function (amplitude)
|
||||
Field_mzm_analytic = cos((pi/2)*v_);
|
||||
|
||||
% Power transfer function (intensity)
|
||||
P_mzm_analytic = Field_mzm_analytic.^2;
|
||||
|
||||
% Imbalance factor in YOUR notation:
|
||||
rho = 1;
|
||||
|
||||
% Push-pull branch voltages (consistent with v_drive = v1 - v2)
|
||||
v1 = +0.5*v_drive; % arm 1
|
||||
v2 = -0.5*v_drive; % arm 2
|
||||
|
||||
% Phases phi1, phi2
|
||||
phi1 = pi * v1 / Vpi;
|
||||
phi2 = pi * v2 / Vpi;
|
||||
|
||||
% Fields: E_in and E_out (exactly your Eq. (mzm_e_field))
|
||||
E_in = E0 .* exp(1i*omega0*t);
|
||||
|
||||
common_phase = exp(-1i * (omega0*L*n_eff/c0)); % exp(-j*omega0*L*n_eff/c0)
|
||||
|
||||
E_out = E0 .* exp(1i*omega0*t) .* common_phase .* 0.5 .* ...
|
||||
( exp(-1i*phi1) + rho .* exp(-1i*phi2) );
|
||||
|
||||
% Transfer function (numerical): E_out/E_in
|
||||
H_num = E_out ./ E_in;
|
||||
|
||||
% Power (normalized)
|
||||
Pnorm_num = abs(H_num).^2; % since |E_out/E_in|^2
|
||||
|
||||
% Ideal TF (analytic) for comparison (rho=1, push-pull)
|
||||
H_ideal = common_phase .* cos( (pi/2) * (v_drive./Vpi) );
|
||||
|
||||
Pnorm_ideal = abs(H_ideal).^2;
|
||||
Pnorm_math = cos( (pi/2) * (v_drive./Vpi) ).^2;
|
||||
|
||||
|
||||
set(groot, 'defaultLegendInterpreter', 'tex');
|
||||
set(groot, 'defaultAxesTickLabelInterpreter', 'tex');
|
||||
set(groot, 'defaultTextInterpreter', 'tex');
|
||||
|
||||
% Normalized voltage axis (multiples of Vpi)
|
||||
v_norm = v_drive./Vpi;
|
||||
|
||||
colfield = [0,0,0]; %is black
|
||||
colpow = linspecer(2);
|
||||
colpow = colpow(1,:);
|
||||
colvdrive = linspecer(2);
|
||||
colvdrive = colvdrive(2,:);
|
||||
|
||||
%% SIGNAL IN
|
||||
figure(1); clf
|
||||
plot(v_norm,t*1e9, 'LineWidth', 1.0,'Color',colvdrive); grid on;
|
||||
ylabel('t [ns]'); xlabel('v_{drive}(t)/V_\pi');
|
||||
title('Drive voltage (normalized)');
|
||||
xlim([min(v_) max(v_)]);
|
||||
% mat2tikz_improved('C:\Users\Silas\Documents\6971e0b65b380ca6d71c837f\02_IMDD_System\tikz\linear_casee\mzm_input_signal.tex');
|
||||
|
||||
|
||||
%% IN/OUT (static transfer) — normalized x-axis + analytic curve
|
||||
if 0
|
||||
figure(2); clf
|
||||
plot(v_, Field_mzm_analytic, 'LineWidth', 1.2,'LineStyle','--','Color',colfield); hold on;% analytic power TF
|
||||
plot(v_, P_mzm_analytic, 'LineWidth', 1.2, 'Color',colpow); hold on;% analytic power TF
|
||||
% show input time signal
|
||||
plot(v_norm,-1+t*1e9, 'LineWidth', 1.0,'Color',colvdrive); grid on;
|
||||
% show output time signal
|
||||
plot(2+t*1e9, Pnorm_num, 'LineWidth', 1.0,'DisplayName','Intensity', 'Color',colvdrive); hold on;
|
||||
plot(2+t*1e9, real(H_ideal), '--', 'LineWidth', 1.0,'DisplayName','Field','Color',colfield); hold on;
|
||||
scatter(v_norm, Pnorm_num, 12, '.', 'LineWidth', 1,'MarkerEdgeColor',colvdrive);
|
||||
scatter(biasV./Vpi,(cos((pi/2)*biasV./Vpi)^2),10,'Marker','o');
|
||||
line([min(v_drive), min(v_drive)]./Vpi,[(cos((pi/2)*min(v_drive)./Vpi)^2), -2],'linewidth',0.5,'color','black','linestyle','--');
|
||||
line([max(v_drive) max(v_drive)]./Vpi,[(cos((pi/2)*max(v_drive)./Vpi)^2), -2],'linewidth',0.5,'color','black','linestyle','--');
|
||||
xline([min(v_norm) max(v_norm)])
|
||||
|
||||
grid on;
|
||||
xlabel('v_{drive}(t)/V_\pi'); ylabel('|E_{out}/E_{in}|^2');
|
||||
% legend
|
||||
xlim([min(v_) max(v_)+1]);
|
||||
ylim([-1 1]);
|
||||
|
||||
% mat2tikz_improved('C:\Users\Silas\Documents\6971e0b65b380ca6d71c837f\02_IMDD_System\tikz\mzm.tex');
|
||||
end
|
||||
%%
|
||||
|
||||
figure(3); clf
|
||||
plot(v_, Field_mzm_analytic, 'LineWidth', 1.2,'LineStyle','--','Color',colfield); hold on;% analytic power TF
|
||||
plot(v_, P_mzm_analytic, 'LineWidth', 1.2, 'Color',colpow); hold on;% analytic power TF
|
||||
|
||||
scatter(v_norm, Pnorm_num, 12, '.', 'LineWidth', 1,'MarkerEdgeColor',colvdrive);
|
||||
scatter(biasV./Vpi,(cos((pi/2)*biasV./Vpi)^2),10,'Marker','o');
|
||||
line([min(v_drive), min(v_drive)]./Vpi,[(cos((pi/2)*min(v_drive)./Vpi)^2), -2],'linewidth',0.5,'color','black','linestyle','--');
|
||||
line([max(v_drive) max(v_drive)]./Vpi,[(cos((pi/2)*max(v_drive)./Vpi)^2), -2],'linewidth',0.5,'color','black','linestyle','--');
|
||||
xline([min(v_norm) max(v_norm)])
|
||||
|
||||
grid on;
|
||||
xlabel('v_{drive}(t)/V_\pi'); ylabel('|E_{out}/E_{in}|^2');
|
||||
% legend
|
||||
xlim([min(v_) max(v_)]);
|
||||
ylim([-1 1]);
|
||||
|
||||
% mat2tikz_improved('C:\Users\Silas\Documents\6971e0b65b380ca6d71c837f\02_IMDD_System\tikz\mzm_tramsfer_function_matlab.tex');
|
||||
|
||||
|
||||
%%
|
||||
|
||||
figure(4); clf
|
||||
% plot(v_, Field_mzm_analytic, 'LineWidth', 1.2,'LineStyle','--','Color',colfield); hold on;% analytic power TF
|
||||
plot(v_, P_mzm_analytic, 'LineWidth', 1.2, 'Color','black'); hold on;% analytic power TF
|
||||
input_dots = linspace(min(v_drive),max(v_drive),4)./Vpi;
|
||||
% input_dots = unique(v_drive_rect)./Vpi;
|
||||
output_dots = (cos((pi/2)*input_dots).^2);
|
||||
scatter(input_dots,output_dots,'Marker','x','LineWidth',1,'MarkerEdgeColor','black');
|
||||
scatter(input_dots,zeros(size(input_dots)),'Marker','^','LineWidth',2,'MarkerEdgeColor','black');
|
||||
% scatter(ones(size(input_dots)),output_dots,'Marker','<','LineWidth',2,'MarkerEdgeColor','black');
|
||||
|
||||
for i = 1:numel(input_dots)
|
||||
% Draw the dashed projection lines
|
||||
line([input_dots(i), input_dots(i)], [output_dots(i), 0], 'linewidth', 0.5, 'color', 'black', 'linestyle', '--', 'handlevisibility', 'off');
|
||||
line([input_dots(i), 1], [output_dots(i), output_dots(i)], 'linewidth', 0.5, 'color', 'black', 'linestyle', '--', 'handlevisibility', 'off');
|
||||
|
||||
% Add the level annotation boxes near the output (y-axis)
|
||||
% Adjust the '1.05' to move the box further right or 'output_dots(i)' for height
|
||||
j = 3-(i-1)*2;
|
||||
text(1, output_dots(i), sprintf('Level %d', j), ...
|
||||
'FontSize', 8, ...
|
||||
'EdgeColor', 'black', ...
|
||||
'BackgroundColor', 'white', ...
|
||||
'Margin', 2);
|
||||
end
|
||||
|
||||
xlim([0,1.5]);
|
||||
ylim([0,1])
|
||||
|
||||
% line([min(v_drive), min(v_drive)]./Vpi,[(cos((pi/2)*min(v_drive)./Vpi)^2), 0],'linewidth',0.5,'color','black','linestyle','--');
|
||||
% line([max(v_drive), max(v_drive)]./Vpi,[(cos((pi/2)*max(v_drive)./Vpi)^2), 0],'linewidth',0.5,'color','black','linestyle','--');
|
||||
|
||||
% mat2tikz_improved('C:\Users\Silas\Documents\6971e0b65b380ca6d71c837f\02_IMDD_System\tikz\linear_casee\mzm_tf.tex');
|
||||
% xticks(sort(input_dots));
|
||||
% yticks(sort(output_dots));
|
||||
grid off
|
||||
|
||||
|
||||
%%
|
||||
% % FIELD TF (only field here; do not mix power into this figure)
|
||||
figure(5); clf
|
||||
% plot(t*1e9, real(H_num), 'LineWidth', 1.0); hold on;
|
||||
% plot(t*1e9, real(H_ideal), '--', 'LineWidth', 1.0,'DisplayName','Field','Color',colfield); hold on;
|
||||
plot(t*1e9, Pnorm_num, 'LineWidth', 1.0,'DisplayName','Intensity', 'Color',colpow); hold on;
|
||||
grid on;
|
||||
xlabel('t [ns]'); ylabel('Re\{E_{out}/E_{in}\}');
|
||||
legend
|
||||
yticks(sort(output_dots));
|
||||
% mat2tikz_improved('C:\Users\Silas\Documents\6971e0b65b380ca6d71c837f\02_IMDD_System\tikz\linear_casee\mzm_output_signal.tex');
|
||||
|
||||
|
||||
|
||||
Reference in New Issue
Block a user