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% Illustrates the use of AiryI.m
% Plots field intensity of a TEM00 mode after clipping at an aperture. 16 beam cross
% sections are calculated starting in the near field ending in the far field
% (takes some time to run).
lambda=10.6e-6;
a=0.005;
F=0.2;
w0=a/sqrt(pi*F);
rmax=a;
nradialpts=50;
nthetapts=36;
for n=1:16
L=n*25*a;
%thetaoffset=20*pi/180;
rseed=[0:rmax/nradialpts:sqrt(rmax)].^2;
thetaseed=[0:360/nthetapts:360]*pi/180;
[theta,r]=meshgrid(thetaseed,rseed);
[x,y]=pol2cart(theta,r);
subplot(4,4,n);
z=AiryI([a,w0,L,lambda,4],r);
h=pcolor(x,y,z); hold on;
%h_contours=contour(x,y,sqrt(x.^2+y.^2),[0.02,0.02],'r');
colormap(bone);
set(h,'EdgeColor','none');
set(h,'FaceColor','interp');
set(gca,'Visible','off');
set(gcf,'Color','black');
axis square
set(gca,'XLim',[-rmax rmax]);
set(gca,'YLim',[-rmax rmax]);
%set(gca,'ZLim',[0 2.5]);
hold off
drawnow;
end
shg;
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