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Nonsquanial GRIN lens modeling

  • 9 March 2023
  • 1 reply
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Hi,

 

I am trying to develop a GRIN lens model for my optical design.  However, the profile of the beam output is not correct.  I would like to learn how I can fix it.

 

Below is a screenshot of the result I have from Zemax 13.  As we can see, the beam only focuses on one axis (y-axis).  The width in the z-axis reminds the same.  I tried to run the simulation using OpticStudio 22.3, but the result reminds the same. 

 

I followed this thread to start my work.

 

 

The GRIN lens I use is from Edmund #64-541

(https://www.edmundoptics.com/p/10mm-dia-810nm-dwl-00mm-wd-nir-coated-grin-lens/19253/)

 

I imported the .step file downloaded from the website and assigned the index based on what I got from the sequential mode. 

 

 

I feel this issue comes from the .step file.  I tried to draw a solid cylinder with 1 mm in diameter and 2.38 mm in length (the same as the dimension of the GRIN lens), but it did not work…  Maybe I should not draw a solid cylinder directly.  Or it was actually caused by other issues. 

 

The .ZAR file is attached for your reference.  I appreciate your help in advance. 

 

Thanks,

Tse-Shao

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Best answer by Christophe.Weisse 27 March 2023, 09:59

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Dear Tse-Shao,

Thanks for sharing the design file - always easier to investigate.

Indeed, the .step file focuses only along 1 axis. Yet, the cylinder volume works OK on my end :
 

GRIN 5 lens with cylinder volume

My feeling is that there is an axis mismatch when using the .Step file. When you import the geometry, it is tilted 90° and the GRIN material seems to keep this initial orientation for some reason.
I can’t figure out, though, why I wouldn’t work with a cylinder volume on your end ?
Please find the .zmx file herewith attached.
 

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