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    [分享]求解光孤子或超短脉冲耦合方程的Matlab程序 [复制链接]

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    离线tianmen
     
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    只看楼主 倒序阅读 楼主  发表于: 2011-06-12
    计算脉冲在非线性耦合器中演化的Matlab 程序 )#0Llx!  
    `XK+Y  
    %  This Matlab script file solves the coupled nonlinear Schrodinger equations of |W;EPQ+<  
    %  soliton in 2 cores coupler. The output pulse evolution plot is shown in Fig.1 of ibxtrt=  
    %  Youfa Wang and Wenfeng Wang, “A simple and effective numerical method for nonlinear x-Fl|kwX.5  
    %   pulse propagation in N-core optical couplers”, IEEE Photonics Technology lett. Vol.16, No.4, pp1077-1079, 2004 ?t"bF:!  
    &Tn7  
    %fid=fopen('e21.dat','w'); MtXd}/  
    N = 128;                       % Number of Fourier modes (Time domain sampling points) Mb\[` 4z  
    M1 =3000;              % Total number of space steps q,fk@GI'2  
    J =100;                % Steps between output of space :qxd s>Xm  
    T =10;                  % length of time windows:T*T0 kOLS<>.  
    T0=0.1;                 % input pulse width #e5*Dr8  
    MN1=0;                 % initial value for the space output location ghVxcK  
    dt = T/N;                      % time step }< m@82\  
    n = [-N/2:1:N/2-1]';           % Index r57rH^Hc  
    t = n.*dt;   TM$Ek^fQ.  
    u10=1.*sech(1*t);              % input to waveguide1 amplitude: power=u10*u10 *h Bo,   
    u20=u10.*0.0;                  % input to waveguide 2 5%%A2FrB.S  
    u1=u10; u2=u20;                 D OGg=`XK1  
    U1 = u1;   #7dM %  
    U2 = u2;                       % Compute initial condition; save it in U !Z`xwk"!  
    ww = 4*n.*n*pi*pi/T/T;         % Square of frequency. Note i^2=-1. Nk/Ms:57y  
    w=2*pi*n./T; 2apQ4)6#[H  
    g=-i*ww./2;                    % w=2*pi*f*n./N, f=1/dt=N/T,so w=2*pi*n./T oQ_n:<3X  
    L=4;                           % length of evoluation to compare with S. Trillo's paper *l\vqgv.Z  
    dz=L/M1;                       % space step, make sure nonlinear<0.05 'P,F)*kh  
    for m1 = 1:1:M1                                    % Start space evolution Ykt(%2L  
       u1 = exp(dz*i*(abs(u1).*abs(u1))).*u1;          % 1st sSolve nonlinear part of NLS $jKeJn8,  
       u2 = exp(dz*i*(abs(u2).*abs(u2))).*u2; bmu<V1[W  
       ca1 = fftshift(fft(u1));                        % Take Fourier transform G##^xFx  
       ca2 = fftshift(fft(u2)); xrky5[XoD  
       c2=exp(g.*dz).*(ca2+i*1*ca1.*dz);               % approximation Gj(UA1~1  
       c1=exp(g.*dz).*(ca1+i*1*ca2.*dz);               % frequency domain phase shift   ||vQW\g  
       u2 = ifft(fftshift(c2));                        % Return to physical space js8GK  
       u1 = ifft(fftshift(c1)); ;3k6_ub  
    if rem(m1,J) == 0                                 % Save output every J steps. tmf= 1M  
        U1 = [U1 u1];                                  % put solutions in U array DU: sQS4  
        U2=[U2 u2]; Zjh9jvsW  
        MN1=[MN1 m1]; DozC>  
        z1=dz*MN1';                                    % output location  !B\[Q$  
      end )#n>))   
    end %D:5 S?{  
    hg=abs(U1').*abs(U1');                             % for data write to excel >5!/&D.q  
    ha=[z1 hg];                                        % for data write to excel Cb/?hT  
    t1=[0 t']; m K@a7fF?  
    hh=[t1' ha'];                                      % for data write to excel file |~3$L\X  
    %dlmwrite('aa',hh,'\t');                           % save data in the excel format .+c YzS] !  
    figure(1) 3((53@s98  
    waterfall(t',z1',abs(U1').*abs(U1'))               % t' is 1xn, z' is 1xm, and U1' is mxn *>XY' -;2e  
    figure(2) 6lc/_&0  
    waterfall(t',z1',abs(U2').*abs(U2'))               % t' is 1xn, z' is 1xm, and U1' is mxn ^. i;,  
    07dUBoq  
    非线性超快脉冲耦合的数值方法的Matlab程序 i|Y_X  
    umWZ]8  
    在研究脉冲在非线性耦合器中的演变时,我们需要求解非线性偏微分方程组。在如下的论文中,我们提出了一种简洁的数值方法。 这里我们提供给大家用Matlab编写的计算程序。   "yCek  
    Youfa Wang and Wenfeng Wang, “A simple and effective numerical method for nonlinear pulse propagation in N-core optical couplers”, IEEE Photonics Technology lett. Vol.16, No.4, pp1077-1079, 2004 tKUy&]T  
    T\ h_8  
    B<Ynx_ 95  
    2)^[SpZ  
    %  This Matlab script file solves the nonlinear Schrodinger equations SEXLi8;/  
    %  for 3 cores nonlinear coupler. The output plot is shown in Fig.2 of r6-'p0|   
    %  Youfa Wang and Wenfeng Wang, “A simple and effective numerical method for nonlinear UVD::  
    %  pulse propagation in N-core optical couplers”, IEEE Photonics Technology lett. Vol.16, No.4, pp1077-1079, 2004 9/k?Lv  
    !u#o"e<qh  
    C=1;                           s=nE'/q1|  
    M1=120,                       % integer for amplitude q[3b i!Q  
    M3=5000;                      % integer for length of coupler pPG@_9qf  
    N = 512;                      % Number of Fourier modes (Time domain sampling points) "lf_`4  
    dz =3.14159/(sqrt(2.)*C)/M3;  % length of coupler is divided into M3 segments,  make sure nonlinearity<0.05. (A*r&Ak[  
    T =40;                        % length of time:T*T0. rS 4'@a  
    dt = T/N;                     % time step &xqe8!FeA  
    n = [-N/2:1:N/2-1]';          % Index #:68}f"$  
    t = n.*dt;   NOa.K)^k  
    ww = 4*n.*n*pi*pi/T/T;        % Square of frequency. Note i^2=-1. XabrX|B#  
    w=2*pi*n./T; F*d{<  
    g1=-i*ww./2; IfZaK([  
    g2=-i*ww./2;                  % w=2*pi*f*n./N, f=1/dt=N/T,so w=2*pi*n./TP=0; CW=-@W7  
    g3=-i*ww./2; >gr6H1  
    P1=0; j1>77C3  
    P2=0; | ~G;M*q  
    P3=1; ~^"cq S(  
    P=0; .6 E7 R  
    for m1=1:M1                 Ac.z6]p  
    p=0.032*m1;                %input amplitude XY| -qd}A  
    s10=p.*sech(p.*t);         %input soliton pulse in waveguide 1 5Wi5`8m  
    s1=s10; R^F99L  
    s20=0.*s10;                %input in waveguide 2 /d >fp  
    s30=0.*s10;                %input in waveguide 3 8}Y( @ %4  
    s2=s20; nu$LWC-  
    s3=s30; rDYq]`  
    p10=dt*(sum(abs(s10').*abs(s10'))-0.5*(abs(s10(N,1)*s10(N,1))+abs(s10(1,1)*s10(1,1))));   j86s[Dty  
    %energy in waveguide 1 %'* |N [  
    p20=dt*(sum(abs(s20').*abs(s20'))-0.5*(abs(s20(N,1)*s20(N,1))+abs(s20(1,1)*s20(1,1))));   JPUDnPr  
    %energy in waveguide 2 ,[bcyf  
    p30=dt*(sum(abs(s30').*abs(s30'))-0.5*(abs(s30(N,1)*s30(N,1))+abs(s30(1,1)*s30(1,1))));   SAG) vmm  
    %energy in waveguide 3 -JZl?hY(  
    for m3 = 1:1:M3                                    % Start space evolution !*|CIxk(  
       s1 = exp(dz*i*(abs(s1).*abs(s1))).*s1;          % 1st step, Solve nonlinear part of NLS G-n`X":$DT  
       s2 = exp(dz*i*(abs(s2).*abs(s2))).*s2; 7B% @f9g  
       s3 = exp(dz*i*(abs(s3).*abs(s3))).*s3; #OWwg`AWv  
       sca1 = fftshift(fft(s1));                       % Take Fourier transform r+0)l:{.  
       sca2 = fftshift(fft(s2)); YQN=.Wtc  
       sca3 = fftshift(fft(s3)); .(S,dG0P  
       sc1=exp(g1.*dz).*(sca1+i*C*sca2.*dz);           % 2nd step, frequency domain phase shift   @;<w"j`r  
       sc2=exp(g2.*dz).*(sca2+i*C*(sca1+sca3).*dz); &r<<4J(t  
       sc3=exp(g3.*dz).*(sca3+i*C*sca2.*dz); }C#YR( ]  
       s3 = ifft(fftshift(sc3)); NE9e br K  
       s2 = ifft(fftshift(sc2));                       % Return to physical space v& XG4 &  
       s1 = ifft(fftshift(sc1)); !gf&l ^)  
    end p]+W1v}V!  
       p1=dt*(sum(abs(s1').*abs(s1'))-0.5*(abs(s1(N,1)*s1(N,1))+abs(s1(1,1)*s1(1,1)))); &9s6p6 eb  
       p2=dt*(sum(abs(s2').*abs(s2'))-0.5*(abs(s2(N,1)*s2(N,1))+abs(s2(1,1)*s2(1,1)))); hkU# lt  
       p3=dt*(sum(abs(s3').*abs(s3'))-0.5*(abs(s3(N,1)*s3(N,1))+abs(s3(1,1)*s3(1,1)))); il-&d]AP  
       P1=[P1 p1/p10]; Vn/6D[}Tu  
       P2=[P2 p2/p10]; X Y4s  
       P3=[P3 p3/p10]; }UGPEf\  
       P=[P p*p]; i]$d3J3  
    end (Z,,H1L  
    figure(1) K.z}%a  
    plot(P,P1, P,P2, P,P3); :za!!^  
    W: ?-d{  
    转自:http://blog.163.com/opto_wang/
     
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    离线ciomplj
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    只看该作者 1楼 发表于: 2014-06-22
    谢谢哈~!~