首页 -> 登录 -> 注册 -> 回复主题 -> 发表主题
光行天下 -> MATLAB,SCILAB,Octave,Spyder -> 求解光孤子或超短脉冲耦合方程的Matlab程序 [点此返回论坛查看本帖完整版本] [打印本页]

tianmen 2011-06-12 18:33

求解光孤子或超短脉冲耦合方程的Matlab程序

计算脉冲在非线性耦合器中演化的Matlab 程序 [Bl $IfU  
98X!uh'  
%  This Matlab script file solves the coupled nonlinear Schrodinger equations of !y.ei1diw  
%  soliton in 2 cores coupler. The output pulse evolution plot is shown in Fig.1 of  ` 2Wl  
%  Youfa Wang and Wenfeng Wang, “A simple and effective numerical method for nonlinear 3"^a rK^N  
%   pulse propagation in N-core optical couplers”, IEEE Photonics Technology lett. Vol.16, No.4, pp1077-1079, 2004 !x`;>0  
h=uiC&B  
%fid=fopen('e21.dat','w'); l R:O k8e  
N = 128;                       % Number of Fourier modes (Time domain sampling points) qlz( W  
M1 =3000;              % Total number of space steps z8 hTZU  
J =100;                % Steps between output of space Ll008.#  
T =10;                  % length of time windows:T*T0 j9{O0[v  
T0=0.1;                 % input pulse width RpBiE8F4  
MN1=0;                 % initial value for the space output location $KoPGgC[  
dt = T/N;                      % time step aQz|!8Is  
n = [-N/2:1:N/2-1]';           % Index b>hBct}  
t = n.*dt;   !SLP8|Cd  
u10=1.*sech(1*t);              % input to waveguide1 amplitude: power=u10*u10 d-6sC@PB  
u20=u10.*0.0;                  % input to waveguide 2 P?Gd}mdX?m  
u1=u10; u2=u20;                 ^%K1R;  
U1 = u1;   +z]:CF  
U2 = u2;                       % Compute initial condition; save it in U lfU"SSQ  
ww = 4*n.*n*pi*pi/T/T;         % Square of frequency. Note i^2=-1. d&PE,$XC  
w=2*pi*n./T; HMEs8.  
g=-i*ww./2;                    % w=2*pi*f*n./N, f=1/dt=N/T,so w=2*pi*n./T gmF_~"^34  
L=4;                           % length of evoluation to compare with S. Trillo's paper htUy2v#V  
dz=L/M1;                       % space step, make sure nonlinear<0.05 H{ n>KZ]\  
for m1 = 1:1:M1                                    % Start space evolution Mr5('9%  
   u1 = exp(dz*i*(abs(u1).*abs(u1))).*u1;          % 1st sSolve nonlinear part of NLS _Ewy^;S%L  
   u2 = exp(dz*i*(abs(u2).*abs(u2))).*u2; !uj!  
   ca1 = fftshift(fft(u1));                        % Take Fourier transform W,9k0t  
   ca2 = fftshift(fft(u2)); ;ZxK3/(7  
   c2=exp(g.*dz).*(ca2+i*1*ca1.*dz);               % approximation 9[t]]  
   c1=exp(g.*dz).*(ca1+i*1*ca2.*dz);               % frequency domain phase shift   Sa h<sb=  
   u2 = ifft(fftshift(c2));                        % Return to physical space L337/8fh  
   u1 = ifft(fftshift(c1)); GsP@ B'  
if rem(m1,J) == 0                                 % Save output every J steps. @!L@UP0  
    U1 = [U1 u1];                                  % put solutions in U array n&2=6$*,k  
    U2=[U2 u2]; eeI9[lTw  
    MN1=[MN1 m1]; 6SW|H"!!  
    z1=dz*MN1';                                    % output location EO o'a  
  end KRnB[$3F1  
end wS F!Xx0  
hg=abs(U1').*abs(U1');                             % for data write to excel 7.lK$J:  
ha=[z1 hg];                                        % for data write to excel s]nGpA[!  
t1=[0 t']; YO.`l~ v  
hh=[t1' ha'];                                      % for data write to excel file %9~kA5Qj  
%dlmwrite('aa',hh,'\t');                           % save data in the excel format  ?;ALF  
figure(1) uJ|5 Ve  
waterfall(t',z1',abs(U1').*abs(U1'))               % t' is 1xn, z' is 1xm, and U1' is mxn DU*g~{8T$  
figure(2) ^td!g1"<  
waterfall(t',z1',abs(U2').*abs(U2'))               % t' is 1xn, z' is 1xm, and U1' is mxn dN$D6*  
M/8#&RycQ  
非线性超快脉冲耦合的数值方法的Matlab程序 J-eA,9J  
@ }zS/LO  
在研究脉冲在非线性耦合器中的演变时,我们需要求解非线性偏微分方程组。在如下的论文中,我们提出了一种简洁的数值方法。 这里我们提供给大家用Matlab编写的计算程序。   Q ^1#xBd  
Youfa Wang and Wenfeng Wang, “A simple and effective numerical method for nonlinear pulse propagation in N-core optical couplers”, IEEE Photonics Technology lett. Vol.16, No.4, pp1077-1079, 2004 ?vht~5'  
+hgaBJy  
OVQxZ~uQ  
 |(J ?#?  
%  This Matlab script file solves the nonlinear Schrodinger equations yO$r'9?,*  
%  for 3 cores nonlinear coupler. The output plot is shown in Fig.2 of T0*TTB&b  
%  Youfa Wang and Wenfeng Wang, “A simple and effective numerical method for nonlinear $ sA~p_]  
%  pulse propagation in N-core optical couplers”, IEEE Photonics Technology lett. Vol.16, No.4, pp1077-1079, 2004 eSvc/CU  
2kp|zX(  
C=1;                           _Ssv:x c,  
M1=120,                       % integer for amplitude hIzPy3  
M3=5000;                      % integer for length of coupler #RLch  
N = 512;                      % Number of Fourier modes (Time domain sampling points) TeGLAt  
dz =3.14159/(sqrt(2.)*C)/M3;  % length of coupler is divided into M3 segments,  make sure nonlinearity<0.05.  eo<~1w  
T =40;                        % length of time:T*T0. vZ_DG}n11  
dt = T/N;                     % time step jziA;6uL  
n = [-N/2:1:N/2-1]';          % Index 2t]! {L  
t = n.*dt;   9|G=KN)P:  
ww = 4*n.*n*pi*pi/T/T;        % Square of frequency. Note i^2=-1. 8,H#t@+MT  
w=2*pi*n./T; :nbW.B3GV  
g1=-i*ww./2; ,h wf  
g2=-i*ww./2;                  % w=2*pi*f*n./N, f=1/dt=N/T,so w=2*pi*n./TP=0; c~0VNuN  
g3=-i*ww./2; m|#(gX|F  
P1=0; *xZQG9`kt  
P2=0; qs8K jG@  
P3=1; qN`]*baS  
P=0; Ro3I/NI>  
for m1=1:M1                 zM8/ s96h  
p=0.032*m1;                %input amplitude @WDqP/4  
s10=p.*sech(p.*t);         %input soliton pulse in waveguide 1 *]>OCGsr  
s1=s10; 4Ow Vt&  
s20=0.*s10;                %input in waveguide 2 z hR_qW+  
s30=0.*s10;                %input in waveguide 3 >ihe|WN  
s2=s20; UQji7K }  
s3=s30; m|Q&Lphb8  
p10=dt*(sum(abs(s10').*abs(s10'))-0.5*(abs(s10(N,1)*s10(N,1))+abs(s10(1,1)*s10(1,1))));   |$|nV^y  
%energy in waveguide 1 D)/XP  
p20=dt*(sum(abs(s20').*abs(s20'))-0.5*(abs(s20(N,1)*s20(N,1))+abs(s20(1,1)*s20(1,1))));   G.q^Zd#.T  
%energy in waveguide 2 /xrq'|r?C  
p30=dt*(sum(abs(s30').*abs(s30'))-0.5*(abs(s30(N,1)*s30(N,1))+abs(s30(1,1)*s30(1,1))));   K_lCDiqG  
%energy in waveguide 3 d@>k\6%j  
for m3 = 1:1:M3                                    % Start space evolution RQK**  
   s1 = exp(dz*i*(abs(s1).*abs(s1))).*s1;          % 1st step, Solve nonlinear part of NLS bcx{_&1p  
   s2 = exp(dz*i*(abs(s2).*abs(s2))).*s2; z7l;|T  
   s3 = exp(dz*i*(abs(s3).*abs(s3))).*s3; ss*2TE7  
   sca1 = fftshift(fft(s1));                       % Take Fourier transform 6 peM4X  
   sca2 = fftshift(fft(s2)); 4K?H-Jco  
   sca3 = fftshift(fft(s3)); `bt)'ERO%#  
   sc1=exp(g1.*dz).*(sca1+i*C*sca2.*dz);           % 2nd step, frequency domain phase shift   We+FP9d%  
   sc2=exp(g2.*dz).*(sca2+i*C*(sca1+sca3).*dz); BI]ut |Qw  
   sc3=exp(g3.*dz).*(sca3+i*C*sca2.*dz); GE3U0w6WbK  
   s3 = ifft(fftshift(sc3)); PEQvEruZ}  
   s2 = ifft(fftshift(sc2));                       % Return to physical space nO.+&kA  
   s1 = ifft(fftshift(sc1)); # V9hG9%8  
end Kn9=a-b?,  
   p1=dt*(sum(abs(s1').*abs(s1'))-0.5*(abs(s1(N,1)*s1(N,1))+abs(s1(1,1)*s1(1,1)))); zC>(!fJqq  
   p2=dt*(sum(abs(s2').*abs(s2'))-0.5*(abs(s2(N,1)*s2(N,1))+abs(s2(1,1)*s2(1,1)))); [2j (\vC!  
   p3=dt*(sum(abs(s3').*abs(s3'))-0.5*(abs(s3(N,1)*s3(N,1))+abs(s3(1,1)*s3(1,1)))); koWb@V]  
   P1=[P1 p1/p10]; $d??(   
   P2=[P2 p2/p10]; e[ k;SSs  
   P3=[P3 p3/p10]; sp |y/r#  
   P=[P p*p]; k s`  
end JpHsQ8<  
figure(1) r`E1<aCr|  
plot(P,P1, P,P2, P,P3); W-ND<=:Up  
0Eg r Q  
转自:http://blog.163.com/opto_wang/
ciomplj 2014-06-22 22:57
谢谢哈~!~
查看本帖完整版本: [-- 求解光孤子或超短脉冲耦合方程的Matlab程序 --] [-- top --]

Copyright © 2005-2025 光行天下 蜀ICP备06003254号-1 网站统计