光波导中光参量放大过程传播到L处的各光波波形图数值仿真matlab代码

%基于铌酸锂光波导中级联的和频与差频效应的波长转换 clear;clf; global tmax tmin delta_t zmin=0;zmax=40;delta_z=0.1; tmin=-20;tmax=20;delta_t=0.1; z=zmin:delta_z:zmax; %长度单位:mm t=tmin:delta_t:tmax; %时间单位:ps c=2.998e8; %光速单位:m/s Pp10=0.5; %泵浦1功率 单位:W Pp20=0.4905; %泵浦2功率 Ps0=0.001; %信号光功率 Ap1=zeros((zmax-zmin)/delta_z+1,(tmax-tmin)/delta_t+1); %分配空间 Ap2=zeros((zmax-zmin)/delta_z+1,(tmax-tmin)/delta_t+1); Asf=zeros((zmax-zmin)/delta_z+1,(tmax-tmin)/delta_t+1); As=zeros((zmax-zmin)/delta_z+1,(tmax-tmin)/delta_t+1); Ac=zeros((zmax-zmin)/delta_z+1,(tmax-tmin)/delta_t+1); Pp1=zeros((zmax-zmin)/delta_z+1,(tmax-tmin)/delta_t+1); Pp2=zeros((zmax-zmin)/delta_z+1,(tmax-tmin)/delta_t+1); Psf=zeros((zmax-zmin)/delta_z+1,(tmax-tmin)/delta_t+1); Ps=zeros((zmax-zmin)/delta_z+1,(tmax-tmin)/delta_t+1); Pc=zeros((zmax-zmin)/delta_z+1,(tmax-tmin)/delta_t+1); PPp1=zeros(1,(zmax-zmin)/delta_z+1); PPp2=zeros(1,(zmax-zmin)/delta_z+1); PPsf=zeros(1,(zmax-zmin)/delta_z+1); PPc=zeros(1,(zmax-zmin)/delta_z+1); tau_0p1=7; %初始脉宽 Ap1(1,:)=sqrt(Pp10)*sech(1.76*t/tau_0p1); tau_0p2=tau_0p1; Ap2(1,:)=sqrt(Pp20)*sech(1.76*t/tau_0p2); tau_0s=7; As(1,:)=sqrt(Ps0)*sech(1.76*t/tau_0s); Asf(1,:)=0; Ac(1,:)=0; bp1=1.53; bp2=0.772*bp1/(bp1-0.772); bsf=0.772; bs=1.55; bc=1/(1/bsf-1/bs); deff=17.2; %有效非线性系数 单位:pm/v u0=4*pi*1e-7; %磁导率 单位:N*s^2/C^2 Aeff=50; %有效相互作用面积 单位:um^2 ksf=deff/c*sqrt(2*c*u0/(Aeff*n2(bp1)*n2(bp2)*n2(bsf))); %和频耦合系数 kdf=deff/c*sqrt(2*c*u0/(Aeff*n2(bs)*n2(bc)*n2(bsf))); %差频耦合系数 delta_k=2*pi*(n2(bp1)/bp1+n2(bp2)/bp2-n2(bs)/bs-n2(bc)/bc); %相位失配 %迭代计算SFG+DFG过程中的脉冲振幅变化 for n=2:1:(zmax-zmin)/delta_z+1 Ap1(n,:)=Ap1(n-1,:)+i/2*beta2(bp1)*delta_z*gradient(gradient(Ap1(n-1,:),delta_t),delta_t)*1e-6+i*2*pi*c/bp1*delta_z*ksf*Asf(n-1,:).*conj(Ap2(n-1,:))*1e-3; Ap2(n,:)=Ap2(n-1,:)-(1/vg(bp2)-1/vg(bp1))*delta_z*gradient(Ap2(n-1,:),delta_t)*1e12+i/2*beta2(bp2)*delta_z*gradient(gradient(Ap2(n-1,:),delta_t),delta_t)*1e-6+i*2*pi*c/bp2*delta_z*ksf*Asf(n-1,:).*conj(Ap1(n-1,:))*1e-3; Asf(n,:)=Asf(n-1,:)-(1/vg(bsf)-1/vg(bp1))*delta_z*gradient(Asf(n-1,:),delta_t)*1e12+i/2*beta2(bsf)*delta_z*gradient(gradient(Asf(n-1,:),delta_t),delta_t)*1e-6+i*2*pi*c/bsf*delta_z*ksf*Ap1(n-1,:).*Ap2(n-1,:)*1e-3+i*2*pi*c/bsf*delta_z*kdf*Ac(n-1,:).*As(n-1,:)*exp(-i*delta_k*delta_z*(n-1)*1e3)*1e-3; As(n,:)=As(n-1,:)-(1/vg(bs)-1/vg(bp1))*delta_z*gradient(As(n-1,:),delta_t)*1e12+i/2*beta2(bs)*delta_z*gradient(gradient(As(n-1,:),delta_t),delta_t)*1e-6+i*2*pi*c/bs*delta_z*kdf*Asf(n-1,:).*conj(Ac(n-1,:))*exp(i*delta_k*delta_z*(n-1)*1e3)*1e-3; Ac(n,:)=Ac(n-1,:)-(1/vg(bc)-1/vg(bp1))*delta_z*gradient(Ac(n-1,:),delta_t)*1e12+i/2*beta2(bc)*delta_z*gradient(gradient(Ac(n-1,:),delta_t),delta_t)*1e-6+i*2*pi*c/bc*delta_z*kdf*Asf(n-1,:).*conj(As(n-1,:))*exp(i*delta_k*delta_z*(n-1)*1e3)*1e-3; Pp1(n,:)=(abs(Ap1(n,:))).^2; %脉冲功率 Pp2(n,:)=(abs(Ap2(n,:))).^2; Psf(n,:)=(abs(Asf(n,:))).^2; Ps(n,:)=(abs(As(n,:))).^2; Pc(n,:)=(abs(Ac(n,:))).^2; PPp1(n)=max(cumtrapz(Pp1(n,:))); %脉冲能量 PPp2(n)=max(cumtrapz(Pp2(n,:))); PPsf(n)=max(cumtrapz(Psf(n,:))); PPc(n)=max(cumtrapz(Pc(n,:))); end %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %画L处泵浦1波形 subplot(3,3,1) plot(t,Pp1(n,:)) title('Pp-t'); xlabel('t/fs');ylabel('泵浦脉冲功率 Pp/W'); grid on %画L处倍频光波形 subplot(3,3,2) plot(t,Psf(n,:)) title('Psh-t'); xlabel('t/fs');ylabel('倍频光脉冲功率 Psh/W'); grid on %画L处信号光波形 subplot(3,3,3) plot(t,Ps(n,:)) title('Ps-t'); xlabel('t/fs');ylabel('信号光脉冲功率 Ps/W'); grid on %画L处差频光波形 subplot(3,3,4) plot(t,Pc(n,:)) title('Pc-t'); xlabel('t/fs');ylabel('差频光脉冲功率 Pc/W'); grid on