function [ BL ] = FSM_BL( Lamda,u,KJ,d )%UNTITLED1 Summary of this function goes here%  Detailed explanation goes heren1=1;n2=SiN(Lamda);ntmp=(n2.^2)./(n1.^2);%SetH(2.3,1);%[KJ,d]=LoadH();R=KJ.*sqrt(sqrt(3)./(2.*pi));   %外徑r=d/2;                          %內徑k0=2.*pi./Lamda;v=k0.*sqrt(n2.^2-n1.^2);%w=k0.*sqrt(n.^2-n1.^2);w=sqrt(v.^2-u.^2);%u=k0.*sqrt(n2.^2-n.^2);S1=r.*u.*besseli(0,r.*w)./(r.*w.*besseli(1,r.*w));S21=besselj(1,R.*u).*bessely(0,r.*u)-besselj(0,r.*u).*bessely(1,R.*u);S22=besselj(1,r.*u).*bessely(1,R.*u)-besselj(1,R.*u).*bessely(1,r.*u);BL=S1-(S21./S22);