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Question

TIR (total internal reflection) error during the lens optimization popping up

  • November 6, 2024
  • 2 replies
  • 274 views

pepe
  • Monochrome
  • 3 replies

Hello, I use OpticStudio 15.5 SP3 and I have an issue with optimizing the design consisting of “of the shelf” components by Thorlabs, reflective collimator, and objective lens. I want to obtain the image in focus, but I get the error stating: Error in target 5. TIR at surface 7!

Possible reason for this behaviour is negative thicknesses: 1. in collimator in order to get the rays reflecting of the mirror, and 2. in lens in order to make the rays go through the lens. If I change the thickness following the reflective collimator to positive (-100 to 100) then the rays reflect inwards. If I change the thicknesses of lens and air after lens from negative to positive, the rays are reflected from back surface of the lens.

 

How do I run optimization without error?

 

 

2 replies

Yang.Yongtao
Fully Spectral
Forum|alt.badge.img
  • Fully Spectral
  • 77 replies
  • November 7, 2024

how about optimizing the system from object NA 0.1→0.12→…0.16?

 

 


pepe
  • Author
  • Monochrome
  • 3 replies
  • November 7, 2024

@Yang.Yongtao I understand that beam diameter is larger than lens diameter, but the light source has numerical aperture of 0.16. That’s why I didn’t change it. It appears that  if I change Criteria from Spot Radius to Wavefront in Optimization wizard the system can be optimized. The same is true if I insert a lens of greater diameter than the light beam diameter. I don’t understand why, but at least I get some results.