Tank1x d2 d22 k02n12 n22 k1x d2212k1x d2 Tank1x d2 k1x d

Tan(k_1x d/2) = [(d/2)^2 k_0^2(n_1^2 - n_2^2) - (k_1x d/2)^2]^1/2/k_1x. d/2 Tan(k_1x d/2) = -k_1x d/2/[(d/2)^2 k_0^2(n_1^2 - n_2^2) - (k_1x d/2)^2]^1/2 d = 10 mu m n_1 = 1.505 n_2 = 1.495 V = 5.7 V = k_0 d/2 squareroot n_1^2 - n_2^2

Solution

d = 10;
n1 = 1.505;
n2 = 1.495;
v = 5.7;
k0 = (2*v)/(d*(sqrt(n1^2-n2^2)));

k1x = 1:0.01:100;

x = k1x .* (d/2.0);

y1 = [];
y2 = [];

for i = 1:length(k1x)
    n1 = sqrt(((d/2.0)^2 * k0^2 * (n1^2-n2^2)) - ((k1x(i) * (d/2.0))^2));
    d1 = k1x(i) * (d/2.0);
    y1(i) = n1 / d1;
    y2(i) = -d1 / n1;
end

plot(x, y1)
hold on

plot(x, y2)
hold off