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?