threezero.m

计算光子晶体光纤四波混频与相对抽运频率的关系

%3段
clc;clear;
j=(-1)^.5
f0=193.5%THz
f01=193.45
f02=f0
f03=193.55
n=2^10
fp0=linspace(-0.8,0.8,n)
fp=f0+fp0
fp01=fp-f01
fp02=fp-f02
fp03=fp-f03
c=3e5%nm/ps
la0=1550%nm
dDla=0.07
lap=c./fp%nm
lapr=3%nm
lar=lap-lapr%nm
db1=2*la0^4*pi*dDla*lapr^2./((lap.*lar).^2).*fp01
db2=2*la0^4*pi*dDla*lapr^2./((lap.*lar).^2).*fp02
db3=2*la0^4*pi*dDla*lapr^2./((lap.*lar).^2).*fp03
alpha=0.2
l1=5/3
l2=5/3
l3=5/3
%eta=alpha^2./(alpha^2+db.^2).*(1+(4*exp(-alpha*l)*(sin(db*l/2).^2))/(1-exp
%(-alpha*l))^2)+j*db1
eta=(abs((exp((-alpha+j*db1)*l1)-1)./((-alpha+j*db1))+exp((-alpha+j*db1)*l1).*(exp((-alpha+j*db2)*l2)-1)./((-alpha+j*db2))+(exp((-alpha+j*db1)*l1)+exp((-alpha+j*db2)*l2)).*(exp((-alpha+j*db3)*l3)-1)./((-alpha+j*db3)))).^2;
eta0=(abs((exp(-alpha*l1)-1)/(-alpha)+exp(-alpha*l1)*(exp(-alpha*l2)-1)/(-alpha)+(exp(-alpha*l1)+exp(-alpha*l2))*(exp(-alpha*l3)-1)/(-alpha))).^2;
g=eta/eta0
plot(fp0,g)
hold on