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Problem in simulation of optically pumped VCSEL rate equation

  1. Apr 5, 2009 #1
    this is a optically pumped VCSEL rate equation...


    ##have to write one editor
    function dy = qwer(t,y)
    dy = zeros(2,1);

    h=6.62e-34; %plank's constant
    c=3e10; % speed of light
    La=42e-7; %active layer thickness
    Ap=154e-10; %pumped area
    lamda_p=1310e-7; % pump wavelength
    eta_abs= 0.0243; %pump absorption coefficient
    A=11e8; %monomolecular recombination coefficient
    B=8.2e-11; %bimolecular recombination coefficient
    C=3.5e-29; %Auger recombination coefficient
    N=6e18;% Carrier density
    Ntr=1.85e18; %career number at transparency
    tn=2.5e-9; %career lifetime (s)
    Bita=3e-5; %spontaneous emission factor
    ts=3.294e-12; %photon lifetime (s)
    eV=1e-30;
    G=2.8522e-6;
    gamma=0.05;
    dy(1)=(((h*c*La*Ap)*(A*N+B*N^2+C*N^3))/(lamda_p*eta_abs*eV))-(y(1)/tn)-G*(y(1)-Ntr)*y(2);
    dy(2)=gamma*G*(y(1)-Ntr)*y(2)-(y(2)/ts)+((Bita*y(1))/tn);
    end

    ##have to write another editor

    tspan = [0 80e-10];
    y0 =[0 0 ];

    [T,Y] = ode45(@qwer,tspan,y0);

    subplot(2,1,1);
    plot(T,Y(:,1),'k');
    title('carrier densities');
    xlabel('time');
    ylabel('densities');
    subplot(2,1,2);
    plot(T,Y(:,2),'k');
    title('photon densities');
    xlabel('time');
    ylabel('densities');

    if i run this code i got this(1.jpg) graph..

    now i want to replace N to y(1) at dy(1) equation
    ##have to write one editor
    function dy = qwer(t,y)
    dy = zeros(2,1);

    h=6.62e-34; %plank's constant
    c=3e10; % speed of light
    La=42e-7; %active layer thickness
    Ap=154e-10; %pumped area
    lamda_p=1310e-7; % pump wavelength
    eta_abs= 0.0243; %pump absorption coefficient
    A=11e8; %monomolecular recombination coefficient
    B=8.2e-11; %bimolecular recombination coefficient
    C=3.5e-29; %Auger recombination coefficient
    Ntr=1.85e18; %career number at transparency
    tn=2.5e-9; %career lifetime (s)
    Bita=3e-5; %spontaneous emission factor
    ts=3.294e-12; %photon lifetime (s)
    eV=1e-30;
    G=2.8522e-6;
    gamma=0.05;
    dy(1)=(((h*c*La*Ap)*(A*y(1)+B*(y(1))^2+C*(y(1))^3))/(lamda_p*eta_abs*eV))-(y(1)/tn)-G*(y(1)-Ntr)*y(2);
    dy(2)=gamma*G*(y(1)-Ntr)*y(2)-(y(2)/ts)+((Bita*y(1))/tn);
    end


    ##have to write another editor

    tspan = [0 80e-10];
    y0 =[0 0 ];

    [T,Y] = ode45(@qwer,tspan,y0);

    subplot(2,1,1);
    plot(T,Y(:,1),'k');
    title('carrier densities');
    xlabel('time');
    ylabel('densities');
    subplot(2,1,2);
    plot(T,Y(:,2),'k');
    title('photon densities');
    xlabel('time');
    ylabel('densities');

    if i run this code i didn't get any graph..

    can anyone plz help me..
     

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  2. jcsd
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