Minimal changes
Add Theory plots for Silas Diss
This commit is contained in:
Silas Oettinghaus
140
Functions/Theory/Dissertation/mach_zehnder_modulator.m
Normal file
140
Functions/Theory/Dissertation/mach_zehnder_modulator.m
Normal file
@@ -0,0 +1,140 @@
|
||||
% Minimal MZM transfer-function demo (sinusoidal drive) — aligned with your notation
|
||||
%
|
||||
% Implements exactly:
|
||||
% E_out(t) = E0 * exp(j*w0*t) * exp(-j*w0*L*n_eff/c0) * 1/2 * [ exp(-j*phi1(t)) + rho*exp(-j*phi2(t)) ]
|
||||
% with phi_{1,2}(t) = pi * v_{1,2}(t)/Vpi
|
||||
%
|
||||
% Push-pull:
|
||||
% v1(t) = +v_drive(t)/2 , v2(t) = -v_drive(t)/2 => phi1 = +pi/2 * v_drive/Vpi, phi2 = -pi/2 * v_drive/Vpi
|
||||
%
|
||||
% And the ideal TF (rho=1):
|
||||
% E_out/E_in = exp(-j*w0*L*n_eff/c0) * cos( (pi/2) * v_drive/Vpi )
|
||||
%
|
||||
% Note: E_in(t) = E0 * exp(j*w0*t) in this script.
|
||||
|
||||
% 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 = 100e9; % [Hz]
|
||||
Nper = 1; % number of periods
|
||||
Vpp = 0.5*Vpi; % [V] peak-to-peak of v_drive(t)
|
||||
|
||||
biasV = 2; % [V] differential bias added to v_drive
|
||||
|
||||
% 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; % rho=1 -> ideal balanced MZM (collapses to ideal TF)
|
||||
|
||||
% Time axis + differential drive voltage v_drive(t)
|
||||
T = Nper/f0;
|
||||
t = (0:1/fs:T-1/fs).';
|
||||
|
||||
v_drive = biasV + (Vpp/2)*sin(2*pi*f0*t); % v_drive(t) (peak = Vpp/2)
|
||||
|
||||
% 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_)]);
|
||||
|
||||
%% IN/OUT (static transfer) — normalized x-axis + analytic curve
|
||||
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');
|
||||
|
||||
|
||||
%%
|
||||
% % FIELD TF (only field here; do not mix power into this figure)
|
||||
figure(3); 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
|
||||
mat2tikz_improved('C:\Users\Silas\Documents\6971e0b65b380ca6d71c837f\02_IMDD_System\tikz\mzm_out.tex');
|
||||
|
||||
|
||||
|
||||
23
Functions/mat2tikz_improved.m
Normal file
23
Functions/mat2tikz_improved.m
Normal file
@@ -0,0 +1,23 @@
|
||||
function mat2tikz_improved(filename)
|
||||
arguments
|
||||
% Default to the path in your example if no argument is provided
|
||||
filename (1,1) string = 'C:\Users\Silas\Documents\Dissertation\00_Examples\tikz\textfig.tikz';
|
||||
end
|
||||
cleanfigure;
|
||||
matlab2tikz(char(filename), ...
|
||||
'width','\fwidth', ...
|
||||
'height','\fheight', ...
|
||||
'showInfo',false, ...
|
||||
'extraAxisOptions',{ ...
|
||||
'legend style={font=\footnotesize}', ...
|
||||
'xlabel style={font=\color{white!15!black},font=\small},',...
|
||||
'ylabel style={font=\color{white!15!black},font=\small},',...
|
||||
'legend columns=1', ...
|
||||
'every axis/.append style={font=\scriptsize}',...
|
||||
'legend columns=1',...
|
||||
'legend style={at={(0.02,0.98)},font=\footnotesize,draw=black!60,rounded corners=2pt,inner sep=1pt,fill=white,column sep=6pt,anchor= north west}',...
|
||||
'legend style={at={(0.02,0.98)},draw=white!0!white,font=\scriptsize,inner sep=0.1pt,fill=white,column sep=1pt,anchor= north west}',...
|
||||
'every axis/.append style={font=\scriptsize}',...
|
||||
});
|
||||
|
||||
end
|
||||
Reference in New Issue
Block a user