1 files changed, 73 insertions, 0 deletions
diff --git a/examples/Hermite_demo.m b/examples/Hermite_demo.m
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+% Illustrates the use of HermiteGaussianE.m, decompose.m and recompose.m by
+% defining an off-center Guassian beam (Fig. 1, Col. 1) and recomposing it 
+% in a basis of Hermite Gaussians defined about the center on the figure.
+% The recomposed beam is shown in Fig. 1, Col. 2, where we have used the
+% first 40 Hermite Gaussian (TEM_mn) modes.  Figure 1, Col. 3 shows the
+% difference between the recomposed beam and the original.  Figure 2 shows
+% the magnitude of the coefficients of the TEM_(l,m) mode in the
+% decomposition.
+
+clear domain;
+screensize=0.1;
+npts=75;
+x=(-screensize:2*screensize/(npts-1):screensize);
+y=x;
+w=0.022;
+R=-1e3;
+deltax=1/sqrt(2)*w;
+deltay=0*w;
+wfactor=1;
+lambda=1.064e-6;
+ploton=[1,1];
+n=40;
+
+[xmesh,ymesh]=meshgrid(x,y);
+domain(:,:,1)=xmesh; domain(:,:,2)=ymesh;
+q=q_(w,R,lambda);
+%zin=exp(-(xmesh.^2+ymesh.^2)/2/q);
+zin=HermiteGaussianE([0,0,q_(w*wfactor,R,lambda),lambda],xmesh+deltax,ymesh+deltay);
+[coeffs,tmat]=decompose(zin,domain,'hg',n,[q,lambda,1e-6]);
+disp(' ');
+dispmat(abs(coeffs));
+zout=recompose(domain,'hg',coeffs,[q,lambda]);
+
+if ploton(1)==1
+    figure(1);
+    subplot(331);
+    h=pcolor(xmesh,ymesh,abs(zin).^2); set(h,'edgecolor','none'); axis square; colorbar; drawnow; shg;
+    title('original intensity');
+    subplot(332);
+    h=pcolor(xmesh,ymesh,abs(zout).^2); set(h,'edgecolor','none'); axis square; colorbar; drawnow; shg;
+    title('recomposed');
+    subplot(333);
+    h=pcolor(xmesh,ymesh,abs(zout).^2-abs(zin).^2); set(h,'edgecolor','none'); axis square; colorbar; drawnow; shg;
+    title('difference');
+    subplot(334);
+    h=pcolor(xmesh,ymesh,real(zin)); set(h,'edgecolor','none'); axis square; colorbar; drawnow; shg;
+    title('original real part');
+    subplot(335);
+    h=pcolor(xmesh,ymesh,real(zout)); set(h,'edgecolor','none'); axis square; colorbar; drawnow; shg;
+    title('recomposed');
+    subplot(336);
+    h=pcolor(xmesh,ymesh,real(zout)-real(zin)); set(h,'edgecolor','none'); axis square; colorbar; drawnow; shg;
+    title('difference');
+    subplot(337);
+    h=pcolor(xmesh,ymesh,imag(zin)); set(h,'edgecolor','none'); axis square; colorbar; drawnow; shg;
+    title('original imaginary part')
+    subplot(338);
+    h=pcolor(xmesh,ymesh,imag(zout)); set(h,'edgecolor','none'); axis square; colorbar; drawnow; shg;
+    title('recomposed')
+    subplot(339);
+    h=pcolor(xmesh,ymesh,imag(zout)-imag(zin)); set(h,'edgecolor','none'); axis square; colorbar; drawnow; shg;
+    title('difference');
+end
+
+if length(ploton)>=2 && ploton(2)==1
+    figure(2);
+    ls=(0:size(coeffs,1)-1);
+    ms=(0:size(coeffs,2)-1);
+    h=pcolor(ls,ms,log10(abs(coeffs.'))); axis square; colorbar; drawnow; shg;
+    title('Log_{10} of coefficients of the modes in the decomposition');
+    xlabel('l');
+    ylabel('m');
+end
+\ No newline at end of file