EM2/plot_brewster.m at master · danielvanpaass/EM2 · GitHub

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function [minTheta,minFv] = plot_brewster(epsilon1,epsilon2,plotflag)
%PLOT_BREWSTER Plots the Fresnel reflection coefficients vs the incident
%angle

if (nargin <= 2)
    plotflag = 'on';
end

N = 200;
N = N+1;

theta = linspace(0,0.5*pi,N);

fresnel_h = zeros(N,1);
fresnel_v = zeros(N,1);

for i = 1:N
    [fresnel_h(i),fresnel_v(i)] = Fresnel_reflection(epsilon1,epsilon2,theta(i));
end

[minFv,mini] = min(abs(fresnel_v));
minTheta = theta(mini);

if (strcmp(plotflag,'on'))
    figure
    plot(theta,abs(fresnel_h))
    hold on
    plot(theta,abs(fresnel_v))
    xline(minTheta);
    yline(0);
    scatter(minTheta,minFv,'r','LineWidth',2)
    hold off
    xticks(0:pi/8:pi/2)
    xticklabels({'0','\pi/8','\pi/4','3\pi/8','\pi/2'})
    axis([0 pi/2 0 1])
    title('Magnitude of the Fresnel Reflection Coefficients')
    xlabel('\theta_i [rad]')
    ylabel('|\Gamma|')
    legend({'|\Gamma_H|','|\Gamma_V|'})
    text(minTheta+0.02,minFv+0.05,[sprintf('Brewster''s Angle =\n'),num2str(minTheta/pi),'\pi rad'])

    figure
    plot(theta,angle(fresnel_h))
    hold on
    plot(theta,angle(fresnel_v))
    xline(minTheta);
    yline(0);
    hold off
    xticks(0:pi/8:pi/2)
    yticks(-pi:pi/2:pi)
    xticklabels({'0','\pi/8','\pi/4','3\pi/8','\pi/2'})
    yticklabels({'-\pi','-\pi/2','0','\pi/2','\pi'})
    axis([0 pi/2 -pi pi])
    title('Phase of the Fresnel Reflection Coefficients')
    xlabel('\theta_i [rad]')
    ylabel('\angle\Gamma [rad]')
    legend({'\angle\Gamma_H','\angle\Gamma_V'})
end

end