How to find out the position matrix from Intensity matrix?

Hi sir,

I sending following program by using this I am finding intensity in the focal plane for an X-polarized (linearly polarized light) beam. By using this program I got intensity in the focal plane. But I facing the problem to locate position of this intensity matrix. How we can get position of intensity, where it is located in the focal plane. Can anyone help me in this regard.

Here kx,ky position vectors in pupil plane.

dim=32;
lamda=531e-9;
k1=2*pi/lamda;
[kx,ky]=meshgrid(-1:2/(dim-1):1);
circ=sqrt(kx.^2+ky.^2)<1;
alp=asin(0.6);
k0=1/sin(alp);
k=512;
kz=sqrt(k0^2-(kx.^2+ky.^2));
Gx=((k0*ky.^2+kz.*kx.^2)./(k0*(kx.^2+ky.^2)));
Gy=sqrt(k0./kz).*((kz-k0).*kx.*ky)./(k0*(kx.^2+ky.^2));
Gz=sqrt(k0./kz).*(kx./k0);
Ex=fftshift(fft2(Gx.*circ,k,k));
Ix=Ex.*conj(Ex);
Ey=fftshift(fft2(Gy.*circ,k,k));
Iy=Ey.*conj(Ey);
Ez=fftshift(fft2(Gz.*circ,k,k));
Iz=Ez.*conj(Ez);
Itot=Ix+Iy+Iz;
figure(1)
imagesc(Itot);
colormap gray;
axis image;
figure(2)
plot(Itot(k/2,:))

[Walter Roberson]

http://www.mathworks.com/matlabcentral/answers/13205-tutorial-how-to-format-your-question-with-markup

http://www.mathworks.com/matlabcentral/answers/7924-where-can-i-upload-images-and-files-for-use-on-matlab-answers

Your question would be easier to understand with a sample intensity image and a description of where in the image we should be looking to see feature you are talking about.

[MOHD]

I required position matrix across total volume 512 X 512 pixels in the

image plane, which showed in figure (1)

[Walter Roberson]

MOHD, imagine that back when I studied in University, 90% of what is known to science now had not yet been discovered, and that was known then was often called by quite different terms than it is at present. With that in mind, perhaps you could explain what "position matrix" means to you.

When I look at the math of what you wrote, my speculation would be that you want to do an ifft2(), but that it should not really be ifft2() of Itot, and that the result you are likely looking for would (I think) be equivalent to the product of the G* functions inside the circle and 0 outside the circle.

[MOHD]

Hi,

I calculated intensity in this program in the focal volume, I know

intensity values but how can I locate this intensity values in the focal

volume?

[Walter Roberson]

Focal volume or focal plane ?

The "Itot" that you calculate is an rectangular array. For any particular row R and column C, what does Itot(R,C) represent?

[MOHD]

In the focal plane, Itot(R,C) for all rows and columns?

[Walter Roberson]

For example, once you have calculated Itot, what does Itot(7, 19) represent? For example does it represent the strength of Zeta Beam that Sardath would use to transport Vath Sarn 7 hours and 19 minutes into the past?