% TUTORIAL about self-phase modulation and nonlinear Schrödinger

clear all, close all;

%%%%%%%% WAVE PARAMETERS %%%%%%%%%%%%%%%%%%
c=3e8; % speed of light m/s
T0= 1.6e-12; %pulse duratio in s
Lambda0=1500e-9; %optical wavelength in m
Omega0=2*pi*c/Lambda0; % pulsation in rad/s

%%%%%%%% TIME - FREQUENCY VECTORS %%%%%%%%%
nt=...; % Total number of points along time
dtau=...; ; % sampling time - 2*Tmax/nt
Tmax = nt*dtau/2; % Total time duration;

tau=(-nt/2:1:nt/2-1)*dtau; % Time vector
Omega=(-nt/2:1:nt/2-1)*pi/Tmax; % Pulsation vector
Freq=(-nt/2:1:nt/2-1)/(2*Tmax); % Frequency vector
Lambda=...; % Wavelength vector

%%%%%% Waveguide PArameters %%%%%%%  %%%%%%%%%
beta2=... ; % dispersion coef in s^2.m-1

LD=... ; % Dispersion Length
    
%%% NONLINEAR PARAMETERS %%%%%%%
Aeff=...; % Effective mode area in m^2
n2 = ...; % nonlinear refractive index in m^2/W
P0=...; % Injected peak power in W
LNL=...; % nonlinear length

N=sqrt(LD/LNL); % Nonlinear parameter 

%%

%%%%%%%% SAMPLING along z %%%%%%%%

dz=...; % sampling length

%%% LENGTH VECTOR %%%%%%%
Linter=1e-3; % Interaction length
k2 = round(Linter/dz,0) ; % Number of step along z

WGLength=0:dz:k2*dz-dz; % Waveguide length in m

%%%%%% PULSE SHAPE %%%%%%%%%%%%%%%%%%%%

sin=exp(-(tau/T0).^2); % gaussian shape
%sin=sech(tau/T0); % sech shape




%%%% DISPERSION OPERATOR %%%%%%%%%%
Dispersion2 =...; % opérateur dispersion sur dz


%% -------NONLINEAR PROPAGATION : DISPERSION + KERR LENS
% SPLIT STEP FOURRIER METHOD
% atténuation is neglected