% The fringe pattern of a perfectly flat slide

n = 1.5;



x = linspace(-1,1);

theta = atan(abs(x));

R = ((cos(theta)-sqrt(n^2-sin(theta).^2))./(cos(theta)+sqrt(n^2-sin(theta).^2))).^2;

F = 4*R./(1-R).^2;





h = 1; %micron

lambda = .6328; %microns

delta = 4*pi*h/lambda*sqrt((n^2-sin(theta).^2));





I = F.*sin(delta/2).^2./(1+F.*sin(delta/2).^2);

plot(x,I);

xlabel('Position along floor');

ylabel('Reflected intensity (Normalized to 1)');

title('Haidinger fringe from a perfectly flat slide');

grid on;