计算脉冲在非线性耦合器中演化的Matlab 程序 M'X,7hZ
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% This Matlab script file solves the coupled nonlinear Schrodinger equations of /`#JM
% soliton in 2 cores coupler. The output pulse evolution plot is shown in Fig.1 of vqoK9
% Youfa Wang and Wenfeng Wang, “A simple and effective numerical method for nonlinear h{\S '8
% pulse propagation in N-core optical couplers”, IEEE Photonics Technology lett. Vol.16, No.4, pp1077-1079, 2004 aS>cXJ;=
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%fid=fopen('e21.dat','w'); ;2?fz@KZ
N = 128; % Number of Fourier modes (Time domain sampling points) GKUjtPu
M1 =3000; % Total number of space steps 4kV$JV.l
J =100; % Steps between output of space [\fwnS_1
T =10; % length of time windows:T*T0 7#Fcn
T0=0.1; % input pulse width BSr#;;\
MN1=0; % initial value for the space output location
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dt = T/N; % time step c*R\fQd
n = [-N/2:1:N/2-1]'; % Index 23houS
t = n.*dt; QAl4w)F
u10=1.*sech(1*t); % input to waveguide1 amplitude: power=u10*u10 ZcHIk{|
u20=u10.*0.0; % input to waveguide 2 !"E/6z2&(k
u1=u10; u2=u20; 77+3CME{'
U1 = u1; W"t^t|H'~
U2 = u2; % Compute initial condition; save it in U \fvm6$ rZ^
ww = 4*n.*n*pi*pi/T/T; % Square of frequency. Note i^2=-1. 5w~J"P6jg
w=2*pi*n./T; 8090+ (U
g=-i*ww./2; % w=2*pi*f*n./N, f=1/dt=N/T,so w=2*pi*n./T ^,f^YL;
L=4; % length of evoluation to compare with S. Trillo's paper +l]>(k.2
dz=L/M1; % space step, make sure nonlinear<0.05 @a=jSB#B
for m1 = 1:1:M1 % Start space evolution 96; gzG@1!
u1 = exp(dz*i*(abs(u1).*abs(u1))).*u1; % 1st sSolve nonlinear part of NLS Cd6th
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u2 = exp(dz*i*(abs(u2).*abs(u2))).*u2; @S5HMJ2=
ca1 = fftshift(fft(u1)); % Take Fourier transform {od@Sl
ca2 = fftshift(fft(u2)); ]j*uD317
c2=exp(g.*dz).*(ca2+i*1*ca1.*dz); % approximation -V"W
c1=exp(g.*dz).*(ca1+i*1*ca2.*dz); % frequency domain phase shift r AqS;@]0
u2 = ifft(fftshift(c2)); % Return to physical space 9`^(M^|c
u1 = ifft(fftshift(c1)); =jxy4`oF
if rem(m1,J) == 0 % Save output every J steps. +RiI5.$=Z
U1 = [U1 u1]; % put solutions in U array VS7
U2=[U2 u2]; ru1^.(W2
MN1=[MN1 m1]; u35"oLV6}#
z1=dz*MN1'; % output location [yc7F0Aw
end el2<W=^M
end '9Q#%E!*
hg=abs(U1').*abs(U1'); % for data write to excel oe<@mz/
ha=[z1 hg]; % for data write to excel BT$Oh4y4
t1=[0 t']; zyP/'X_~:
hh=[t1' ha']; % for data write to excel file *L Y6hph"
%dlmwrite('aa',hh,'\t'); % save data in the excel format DH i@ujr
figure(1) +nB0O/m'U
waterfall(t',z1',abs(U1').*abs(U1')) % t' is 1xn, z' is 1xm, and U1' is mxn 23'{{@30
figure(2) Gfy9YH~
waterfall(t',z1',abs(U2').*abs(U2')) % t' is 1xn, z' is 1xm, and U1' is mxn {(tR<z)
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非线性超快脉冲耦合的数值方法的Matlab程序
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在研究脉冲在非线性耦合器中的演变时,我们需要求解非线性偏微分方程组。在如下的论文中,我们提出了一种简洁的数值方法。 这里我们提供给大家用Matlab编写的计算程序。 5'`DrTOA
Youfa Wang and Wenfeng Wang, “A simple and effective numerical method for nonlinear pulse propagation in N-core optical couplers”, IEEE Photonics Technology lett. Vol.16, No.4, pp1077-1079, 2004 2\#$::B9
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% This Matlab script file solves the nonlinear Schrodinger equations ZnuRy:
% for 3 cores nonlinear coupler. The output plot is shown in Fig.2 of MJH>rsTQ
% Youfa Wang and Wenfeng Wang, “A simple and effective numerical method for nonlinear 7A$mZPKh
% pulse propagation in N-core optical couplers”, IEEE Photonics Technology lett. Vol.16, No.4, pp1077-1079, 2004 q['3M<q
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C=1; nYvkeT
M1=120, % integer for amplitude d@b2XCh<K
M3=5000; % integer for length of coupler B|M@o^Tf
N = 512; % Number of Fourier modes (Time domain sampling points) Dk2Zl
dz =3.14159/(sqrt(2.)*C)/M3; % length of coupler is divided into M3 segments, make sure nonlinearity<0.05. 4N3O<)C)@
T =40; % length of time:T*T0. m*i,|{UZ
dt = T/N; % time step &t