Prev: Dual axis plots
Next: WindowScrollWheelFcn and ginput problem
From: Peter Schreiber on 4 Oct 2009 22:39
Hi guys,
I could compute the diffraction pattern of a small slit where the slit was in the order of several 10s of microns, using FFT2.

I then tried to compute the diffraction spot (PSF) of an aberrated imaging system by propagating the aberrated wavefront from the exit pupil to the image plane.

I'm not sure how to overcome the sampling issues in which I ran into, for optical
systems with exit pupils of ~50mm.

In order to get acceptable sampling in the image plane I would have to use many grid points in the Exit pupil (e.g. fft2 of matrices of dimensions 4096x4096), which doesn't work for computation time/memory.

For all optics people using matlab.... am I missing something? Any ideas how software like Zemax handles the PSF computations?

Best Regards,
Peter
From: Bruno Luong on 5 Oct 2009 02:43
"Peter Schreiber" <schreiber.peter15(a)gmail.com> wrote in message
> In order to get acceptable sampling in the image plane I would have to use many grid points in the Exit pupil (e.g. fft2 of matrices of dimensions 4096x4096), which doesn't work for computation time/memory.

Peter, apply FFT2 on 4096x4096 image does not seem very demanding to me:

>
>> A=rand(4096);
>> tic; B=fft2(A); toc
Elapsed time is 1.678017 seconds.
>> whos
Name Size Bytes Class Attributes

A 4096x4096 134217728 double
B 4096x4096 268435456 double complex

I miss something?

Bruno
 | 
Pages: 1
Prev: Dual axis plots
Next: WindowScrollWheelFcn and ginput problem