Skip to main content
Question

Question about Physical Optics Propagation plot


Leon
  • Infrared
  • 13 replies

I have a Gaussian to flattop beam shaper, the layout is attached, the website does not alow me to upload Zemax file. The POP irradiance plot shows strange not-rotational-symmetric wide fringes, although the Guassian beam data used in the layout and POP are exactly the same and the system is rotational symmetric. If converting this system is to NSC, there is no such wide fringes. Can someone explain this? Thanks.

 

4 replies

Forum|alt.badge.img
  • Fully Spectral
  • 104 replies
  • June 4, 2025

Hi,

This is called aliasing (you see aliases -- copies -- of the pattern). The resolution at an earlier position in the system is too coarse or the array lateral extent too small (depends on the propagation used). In general, you need to increase sampling or size in prior planes until there are no such weird artefacts.

 

 


Leon
  • Author
  • Infrared
  • 13 replies
  • June 4, 2025

Hi Ray: 

Thank you for help. I increase the sampling from 1024 to 4096, the aliasing is gone, that is great.


David
Luminary
Forum|alt.badge.img+4
  • Luminary
  • 337 replies
  • June 5, 2025

To check for aliasing, it is best to inspect the phase plot. There is an excellent three part article on POP by Erin Elliott Here.

Kind regards,

David
 

 


Leon
  • Author
  • Infrared
  • 13 replies
  • June 6, 2025

Thank you David for the reply


Reply


Cookie policy

We use cookies to enhance and personalize your experience. If you accept you agree to our full cookie policy. Learn more about our cookies.

 
Cookie settings