he11.m

本软件使用matlab预言编写

function [ HE ] = HE11( Lamda,u,KJ,d,f,n1,n2 )
%等效普通光纤后计算HE11模
%n2=CladN(Lamda,KJ,d);
%n1=SiN(Lamda);
%ntmp=(n2.^2)./(n1.^2);

%f=0.625;
r=f.*KJ;                          %内径
k0=2.*pi./Lamda;
v=k0.*sqrt(n1.^2-n2.^2);
%w=k0.*sqrt(n.^2-n1.^2);
w=sqrt(v.^2-u.^2);
%u=k0.*sqrt(n2.^2-n.^2);
V=v.*r;
U=u.*r;
W=w.*r;
Beta=sqrt((k0.*n1).^2-u.^2);
%f=(1./U.^2+1./W.^2).*(1./U.^2+ntmp./W.^2);
%ktmp=1./W.^2+besselk(0,W)./(W.*besselk(1,W));
%s1=besselj(0,U)./besselj(1,U);
%s2=1./U+U.*(1+ntmp).*(ktmp)./2;
%s3=U.*sqrt(((1-ntmp).*ktmp).^2+4.*f)./2;
%HE=s1-s2+s3;
s1=besselj(0,U)./(U.*besselj(1,U));
s21=1./U.^2;
s22=(n1.^2+n2.^2)./(2.*n1.^2).*(1./W.^2+besselk(0,W)./(W.*besselk(1,W)));
s31=((n1.^2-n2.^2)./(2.*n1.^2).*(1./W.^2+besselk(0,W)./(W.*besselk(1,W)))).^2;
s32=((Beta./(k0.*n1)).*(V./(U.*W)).^2).^2;
HE=s21+s22-sqrt(s31+s32)-s1;