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Paraxial lens mirror in a medium

  • May 24, 2021
  • 4 replies
  • 126 views

Hi,

 

I try to simulate a system that is inside a medium(n=1.5) and would like to use ideal mirror lenses. I tried to use a paraxial lens and to set the material to mirror, but had to adjust the focal length to a value 1.5 smaller compared to the right. The focal length of an ideal lens is not supposed to change because of the material. What would be the right way to define the surface?

 

Thanks,

Leonid

4 replies

David.Nguyen
Luminary
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  • Luminary
  • 1159 replies
  • May 27, 2021

Hi Leonid,

Could you use a ZPL Macro Solve for the job?

I'm thinking about something like:

air_focal_length = 5
surface_number = SOSO(0)-1
wave_number = 1
INDX_CODE = OCOD('INDX')
refractive_index = OPEV(INDX_CODE, surface_number, wave_number, 0, 0, 0, 0)
SOLVERETURN air_focal_length / refractive_index

Which you would apply on the Focal Length cell of your paraxial surface. I'm also attaching an example, which contains my macro, for you to try. The solve uses the refractive index at the surface right before itself: SOSO(0). The desired focal length in air is hard-coded in the macro, but you could pick up a cell value from a dummy surface to parametrize it.

Let me know if it makes sense.

Kind regards,

David


  • Author
  • Infrared
  • 5 replies
  • May 29, 2021

Hi David,

 

Thank you for the reply. I understand your example(and what I did so far), but we expect the focusing distnace of the ideal mirrored lens to be eaual to the focal length as there is no refraction(all the tracing is in n=1.5 medium).

Thanks,

Leonid


David.Nguyen
Luminary
Forum|alt.badge.img+2
  • Luminary
  • 1159 replies
  • May 31, 2021

Hi Leonid,

Got you, sorry to hear it didn't help.

I can't comment for this design choice of the paraxial lens surface though.

Perhaps, someone from Zemax might be able to give you a better justification.

Take care,

David


  • Author
  • Infrared
  • 5 replies
  • June 1, 2021

Thanks David