切换到宽版
  • 广告投放
  • 稿件投递
  • 繁體中文
    • 8891阅读
    • 1回复

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

    上一主题 下一主题
    离线tianmen
     
    发帖
    58
    光币
    15
    光券
    0
    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 d<Os TA  
    s z\RmX  
    %  This Matlab script file solves the coupled nonlinear Schrodinger equations of qck/b  
    %  soliton in 2 cores coupler. The output pulse evolution plot is shown in Fig.1 of ]x G8vy  
    %  Youfa Wang and Wenfeng Wang, “A simple and effective numerical method for nonlinear cP1jw%3P  
    %   pulse propagation in N-core optical couplers”, IEEE Photonics Technology lett. Vol.16, No.4, pp1077-1079, 2004 UIl_& |  
    'O`3FI  
    %fid=fopen('e21.dat','w'); q KM]wu0Et  
    N = 128;                       % Number of Fourier modes (Time domain sampling points) .+Ej%|l%  
    M1 =3000;              % Total number of space steps W.|6$hRl)  
    J =100;                % Steps between output of space JqUVGEg  
    T =10;                  % length of time windows:T*T0 c6HU'%v  
    T0=0.1;                 % input pulse width #$w#"Nr9k  
    MN1=0;                 % initial value for the space output location 2mUu3fZ  
    dt = T/N;                      % time step wB)+og-^1f  
    n = [-N/2:1:N/2-1]';           % Index 3CE8+PnT  
    t = n.*dt;   nnG2z@$-  
    u10=1.*sech(1*t);              % input to waveguide1 amplitude: power=u10*u10 Q 8rtZ  
    u20=u10.*0.0;                  % input to waveguide 2 Oi0;.< kX  
    u1=u10; u2=u20;                 +V@=G &Ou0  
    U1 = u1;   ;}~=W!yz  
    U2 = u2;                       % Compute initial condition; save it in U "Y!dn|3  
    ww = 4*n.*n*pi*pi/T/T;         % Square of frequency. Note i^2=-1. $vBU}~l7  
    w=2*pi*n./T; Nd_@J&  
    g=-i*ww./2;                    % w=2*pi*f*n./N, f=1/dt=N/T,so w=2*pi*n./T BFO Fes`>~  
    L=4;                           % length of evoluation to compare with S. Trillo's paper 6p " c ^  
    dz=L/M1;                       % space step, make sure nonlinear<0.05 o"FiM5L^.  
    for m1 = 1:1:M1                                    % Start space evolution #Qr4Ke$g[l  
       u1 = exp(dz*i*(abs(u1).*abs(u1))).*u1;          % 1st sSolve nonlinear part of NLS *d@Hnu"q  
       u2 = exp(dz*i*(abs(u2).*abs(u2))).*u2; F}]_/cY7B  
       ca1 = fftshift(fft(u1));                        % Take Fourier transform `t1$Ew<  
       ca2 = fftshift(fft(u2)); pxxFm~"d  
       c2=exp(g.*dz).*(ca2+i*1*ca1.*dz);               % approximation j7 =3\SO  
       c1=exp(g.*dz).*(ca1+i*1*ca2.*dz);               % frequency domain phase shift   pK9^W T@  
       u2 = ifft(fftshift(c2));                        % Return to physical space 2&0<$>  
       u1 = ifft(fftshift(c1)); XO#)i6}G  
    if rem(m1,J) == 0                                 % Save output every J steps. )$B+ 3f  
        U1 = [U1 u1];                                  % put solutions in U array #/Fu*0/)`  
        U2=[U2 u2]; 38rZ`O*D  
        MN1=[MN1 m1]; D:E~yh)$-  
        z1=dz*MN1';                                    % output location } +4Bf+u:  
      end b 0b9#9x  
    end qb4;l\SfT  
    hg=abs(U1').*abs(U1');                             % for data write to excel $Je"z]cy-  
    ha=[z1 hg];                                        % for data write to excel &H&P)Px*_  
    t1=[0 t']; 5%+}rSn7  
    hh=[t1' ha'];                                      % for data write to excel file 3Jm'q,TC  
    %dlmwrite('aa',hh,'\t');                           % save data in the excel format 'd^gRH<z  
    figure(1) .w_`d'}  
    waterfall(t',z1',abs(U1').*abs(U1'))               % t' is 1xn, z' is 1xm, and U1' is mxn 7J;~ &x  
    figure(2) ^<\} Y  
    waterfall(t',z1',abs(U2').*abs(U2'))               % t' is 1xn, z' is 1xm, and U1' is mxn 3DAGW"F  
    R.H\b!  
    非线性超快脉冲耦合的数值方法的Matlab程序 kc'0NE4oq  
    X8 )>}#:  
    在研究脉冲在非线性耦合器中的演变时,我们需要求解非线性偏微分方程组。在如下的论文中,我们提出了一种简洁的数值方法。 这里我们提供给大家用Matlab编写的计算程序。   h+3Z.WKhwP  
    Youfa Wang and Wenfeng Wang, “A simple and effective numerical method for nonlinear pulse propagation in N-core optical couplers”, IEEE Photonics Technology lett. Vol.16, No.4, pp1077-1079, 2004 2 dD<]  
    RLz`aBT  
    _P<lG[V  
    fG2&/42J  
    %  This Matlab script file solves the nonlinear Schrodinger equations "&#W Mi  
    %  for 3 cores nonlinear coupler. The output plot is shown in Fig.2 of OawrS{  
    %  Youfa Wang and Wenfeng Wang, “A simple and effective numerical method for nonlinear 6 2`PK+  
    %  pulse propagation in N-core optical couplers”, IEEE Photonics Technology lett. Vol.16, No.4, pp1077-1079, 2004 ; Uqx&5P}  
    'e>sHL  
    C=1;                           DRW.NL o  
    M1=120,                       % integer for amplitude 2c~?UK[1  
    M3=5000;                      % integer for length of coupler s#4ew}  
    N = 512;                      % Number of Fourier modes (Time domain sampling points) !mxh]x<e  
    dz =3.14159/(sqrt(2.)*C)/M3;  % length of coupler is divided into M3 segments,  make sure nonlinearity<0.05. C^ " Hj  
    T =40;                        % length of time:T*T0. bsi q9$F  
    dt = T/N;                     % time step DIqT>HHZ  
    n = [-N/2:1:N/2-1]';          % Index aE\BAbD7  
    t = n.*dt;   ,(0XsBL  
    ww = 4*n.*n*pi*pi/T/T;        % Square of frequency. Note i^2=-1. y8hg8J|  
    w=2*pi*n./T; ?>.g;3E$  
    g1=-i*ww./2; )fMX!#KP  
    g2=-i*ww./2;                  % w=2*pi*f*n./N, f=1/dt=N/T,so w=2*pi*n./TP=0; r\n h.}s  
    g3=-i*ww./2; @`;Y/',  
    P1=0; "h^#<bPN  
    P2=0; PyT}}UKj:  
    P3=1; H'0*CiHes  
    P=0; g<iwxF  
    for m1=1:M1                 k<'vP{  
    p=0.032*m1;                %input amplitude 4 ?@uF[  
    s10=p.*sech(p.*t);         %input soliton pulse in waveguide 1 S`c]Fc  
    s1=s10; ?gR\A8:8  
    s20=0.*s10;                %input in waveguide 2 22/?JWL>  
    s30=0.*s10;                %input in waveguide 3 }1]!#yMfq  
    s2=s20; BY4  R@)  
    s3=s30; Iwt2}E(e  
    p10=dt*(sum(abs(s10').*abs(s10'))-0.5*(abs(s10(N,1)*s10(N,1))+abs(s10(1,1)*s10(1,1))));   {1@4}R4  
    %energy in waveguide 1 # HM\ a  
    p20=dt*(sum(abs(s20').*abs(s20'))-0.5*(abs(s20(N,1)*s20(N,1))+abs(s20(1,1)*s20(1,1))));   ^wO_b'@v  
    %energy in waveguide 2 "_1-IE  
    p30=dt*(sum(abs(s30').*abs(s30'))-0.5*(abs(s30(N,1)*s30(N,1))+abs(s30(1,1)*s30(1,1))));   4ljvoJ}xjr  
    %energy in waveguide 3 eY 4`k  
    for m3 = 1:1:M3                                    % Start space evolution siRnH(^ J  
       s1 = exp(dz*i*(abs(s1).*abs(s1))).*s1;          % 1st step, Solve nonlinear part of NLS EK8E  
       s2 = exp(dz*i*(abs(s2).*abs(s2))).*s2; \Qi#'c$5+a  
       s3 = exp(dz*i*(abs(s3).*abs(s3))).*s3; V"7<[u]K|  
       sca1 = fftshift(fft(s1));                       % Take Fourier transform LN.Bd,  
       sca2 = fftshift(fft(s2)); }r~v,KDb  
       sca3 = fftshift(fft(s3)); /G)KkBC  
       sc1=exp(g1.*dz).*(sca1+i*C*sca2.*dz);           % 2nd step, frequency domain phase shift   _ 7BF+*T  
       sc2=exp(g2.*dz).*(sca2+i*C*(sca1+sca3).*dz); X&9^&U=e  
       sc3=exp(g3.*dz).*(sca3+i*C*sca2.*dz); FU5LY XCs  
       s3 = ifft(fftshift(sc3)); ?K4.L?D#J  
       s2 = ifft(fftshift(sc2));                       % Return to physical space 5xMA~I0c  
       s1 = ifft(fftshift(sc1)); 7TV>6i+7  
    end tIxhSI^  
       p1=dt*(sum(abs(s1').*abs(s1'))-0.5*(abs(s1(N,1)*s1(N,1))+abs(s1(1,1)*s1(1,1)))); j$|j8?  
       p2=dt*(sum(abs(s2').*abs(s2'))-0.5*(abs(s2(N,1)*s2(N,1))+abs(s2(1,1)*s2(1,1)))); -Ap2NpZ"t  
       p3=dt*(sum(abs(s3').*abs(s3'))-0.5*(abs(s3(N,1)*s3(N,1))+abs(s3(1,1)*s3(1,1)))); Ho)t=qn  
       P1=[P1 p1/p10]; [>$\s=` h  
       P2=[P2 p2/p10]; V`g\ja*Y  
       P3=[P3 p3/p10]; bIb6yVnHi  
       P=[P p*p]; B_."?*|w  
    end C,|nmlDN  
    figure(1) C`NBHRa>  
    plot(P,P1, P,P2, P,P3); W( &Go'9e"  
    >}<29Ii  
    转自:http://blog.163.com/opto_wang/
     
    分享到
    离线ciomplj
    发帖
    319
    光币
    1
    光券
    0
    只看该作者 1楼 发表于: 2014-06-22
    谢谢哈~!~