
138 Optical Fiber Communication Systems with MATLAB
®
and Simulink
®
Models
% beta31 = (S - (4*π*c./lambda.^3))./(2*π*c./lambda.^2)
%----------------------------------------------------
gamma = 2e24*π*n2/(lambda*Aeff);
% nonlinearity coef (km^-1.W^-1)
t = ((1:nt)’-(nt+1)/2)*dt;
% vector of t values (ps)
t1 = [(-nt/2+1:0)]’*dt;
% vector of t values (ps)
t2 = [(1:nt/2)]’*dt;
% vector of t values (ps)
w = 2*π*[(0:nt/2-1),(-nt/2:-1)]’/T;
% vector of w values (rad/ps)
v = 1000*[(0:nt/2-1),(-nt/2:-1)]’/T;
% vector of v values (GHz)
vs = fftshift(v);
% swap halves for plotting
v_tmp = 1000*[(-nt/2:nt/2-1)]’/T;
% STARTING FIELD
L = nz*dz
Lnl = 1/(P0*gamma)
% nonlinear ...