%三維圖SPBS
z=0:40:4000;
z1=4000:10:5000
f=11000:4:11400;
fB=11200;
fB1=11100;
fBi=60;
S=13.9174e-4;
a_b=1.2222e-6;
a=0.046e-3;
g=5e-11;
A=6.4e-11;
c=3e+8;  %光速
n=1.45;  %折射率
v=c/n;   %光纖中的光速
W=150e-9;  %脈沖寬度150ns
Pp0=4e-3;
[F,Z]=meshgrid(f,z);
P=a_b*S*Pp0*exp(-2*a*Z)*v*W/2;
Q=1./(1+((F-fB)/(fBi/2)).^2);
I=P*Q;
[F,Z1]=meshgrid(f,z1);
P1=a_b*S*Pp0*exp(-2*a*Z1)*v*W/2;
Q1=1./(1+((F-fB1)/(fBi/2)).^2);
I1=P1*Q1;
mesh(Z,F,I);
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hold on
mesh(Z1,F,I1);
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