在光波导理论中,求解波导色散曲线的常用数值方法之一是效折射率法,本文给出了有效折射率求解思路,并给出了具体的matlab程序,可供学习集成光学的学生参考使用。

for i = 1:2000

NTEe = linspace(1.5100, NTMx(i), 4000);

aTE = xTE_DispersionFun(NTEe, NTMx(i), m);

for j = 1:4000

if(abs(aTE(j) - dTM(i)) < 2e-3)

V(k) = 2*dTM(i)*sqrt(1.5360^2 - 1.5100^2);

b(k) = (NTEe(j)^2 - 1.5100^2)/(1.5360^2 - 1.5100^2);

k = k+1;

end;

end;

end;

plot(V,b,'b');

hold on;

pause;

clear V b;

end;

end;

axis([0, 5, 0, 1]);

xlabel('V');

ylabel('b');

title('归一化色散曲线 a:d = 1:1');

gtext('E11');gtext('E12');gtext('E21');gtext('E22');

zoom on;

% a:d = 2:1

figure(2);

% x方向偏振

NTEx = linspace(1.5100, 1.5370, 2000);

for n = 0:1

dTE = yTE_DispersionFun(NTEx, n);

for m = 0:1

k = 1;

for i = 1:2000

if( NTEx(i) <= 1.5360)

NTMe = linspace(1.5100, NTEx(i), 4000);

aTM = xTM_DispersionFun(NTMe, NTEx(i), m);

for j = 1:4000