Dear Zemax Team,

I shortly designed a high numerical aperture system (NA>0.9) and did a tolerancing. The system is a rotational symmetric objective with spherical surfaces only. Useably quite simple for a ray tracer. 

Subsequently, I performed a MonteCarlo tolerancing by slightly shifting lenses and surfaces and by modifying surface thicknesses by a bit. Almost every system that is created in the MC analysis has a wavefront deformation as follows. It shows a large discontinuity at the edge of the pupil:

Obviously, this WFRMS is not real and hampers an evaluation of the system.

If the entrance pupil radius of this tolerated system is slightly reduced (less than 1%), the resulting wavefront looks as follows. The discontinuity disappears since it originated at the edge of the pupil:

Ray aiming will not help since the stop is in front of the objective. I tried it nevertheless, it doesn’t change anything.

I am estonished since the displacement of surfaces is in the order of 1 µm, I didnt expect any TIR. The angle of incidences of marginal rays at the surfaces is moderate high. Moreover, if I increase the entrance pupil by 5%, still all rays are transmitted according to the ray tracing. 

Is this a bug? Is there any possibility to avoid this discontinuity in my MonteCarlo analyzation?

Thanks and best regards,

Gregor