Kretschmann.zip

%共振角 clc clear e1=-101.670111-i*11.7766;%e1=-17-i*0.5;Ag632.8%e1=-30.2764+i*0.829;%Ag850 e0=1.0^2; e2=1.0^2; e3=1.446^2;%金属膜下的介质的介电常数 d1=1:30; d1=50; d1=d1*10^(-9);%Au d2=1000*10^(-9);%Air fai1=0:0.01:90-0.01; %fai1=42.8; fai=fai1.*pi./180; lan0=1590*10^(-9); c=3*10^8; k0=2*pi.*(e0-e3.*(sin(fai)).^2).^0.5./lan0; k1=2*pi.*(e1-e3.*(sin(fai)).^2).^0.5./lan0; k2=2*pi.*(e2-e3.*(sin(fai)).^2).^0.5./lan0; k3=2*pi.*(e3-e3.*(sin(fai)).^2).^0.5./lan0; r10=(e0.*k1-e1.*k0)./(e0.*k1+e1.*k0); r21=(e1.*k2-e2.*k1)./(e1.*k2+e2.*k1); r32=(e2.*k3-e3.*k2)./(e2.*k3+e3.*k2); %r10=abs(r10);r21=abs(r21);r21=abs(r21); de1=k1.*d1; de2=k2.*d2; r210=(r21+r10.*exp(-2.*de1.*i))./(1+r21.*r10.*exp(-2.*de1.*i)); %r210=real(r210); r3210=(r32+r210.*exp(-2.*de2.*i))./(1+r32.*r210.*exp(-2.*de2.*i)); %r3210=abs(r3210); R=r3210.^2; R=abs(R); %R=R./max(R); %plot(d1*10^(+9),R);grid on plot(fai./pi.*180,R);grid on min(R) find(R<=min(R)).*0.01