计算脉冲在非线性耦合器中演化的Matlab 程序 ZliJc7lss
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% This Matlab script file solves the coupled nonlinear Schrodinger equations of ZSUbPz
% soliton in 2 cores coupler. The output pulse evolution plot is shown in Fig.1 of ;4!,19AT
% Youfa Wang and Wenfeng Wang, “A simple and effective numerical method for nonlinear 3Aqw)B'"_
% pulse propagation in N-core optical couplers”, IEEE Photonics Technology lett. Vol.16, No.4, pp1077-1079, 2004 d<@SRHP(
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%fid=fopen('e21.dat','w'); lO>9Q]S<
N = 128; % Number of Fourier modes (Time domain sampling points) DMc H, _(
M1 =3000; % Total number of space steps u@{z
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J =100; % Steps between output of space FD+y?UF
T =10; % length of time windows:T*T0 $ncJc
T0=0.1; % input pulse width [2 yxTK
MN1=0; % initial value for the space output location NhgzU+)+
dt = T/N; % time step K!\$M BI
n = [-N/2:1:N/2-1]'; % Index H E'1Wa0r
t = n.*dt; xX5EhVR
u10=1.*sech(1*t); % input to waveguide1 amplitude: power=u10*u10 3R=R k
u20=u10.*0.0; % input to waveguide 2 ?}tWI7KI
u1=u10; u2=u20; W|yFjE&dr
U1 = u1; ALOS>Bi&
U2 = u2; % Compute initial condition; save it in U 'Wv`^{y <^
ww = 4*n.*n*pi*pi/T/T; % Square of frequency. Note i^2=-1. 6
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w=2*pi*n./T; m,"N4a@
g=-i*ww./2; % w=2*pi*f*n./N, f=1/dt=N/T,so w=2*pi*n./T V(5=-8k
L=4; % length of evoluation to compare with S. Trillo's paper b;K];o-/f
dz=L/M1; % space step, make sure nonlinear<0.05 dHUcu@,
for m1 = 1:1:M1 % Start space evolution cj5;XK
u1 = exp(dz*i*(abs(u1).*abs(u1))).*u1; % 1st sSolve nonlinear part of NLS D J:N
u2 = exp(dz*i*(abs(u2).*abs(u2))).*u2; %!vgAH4
ca1 = fftshift(fft(u1)); % Take Fourier transform JR_s-&