I want to build a toy model composed of a grating and a diaphragm, as in the following diagram:
![](https://uploads-us-west-2.insided.com/zemax-en/attachment/6657d41f-e345-4d6c-8a1e-59c018ae92e2.png)
Namely, the stop surface should be the diaphragm. However, when I build this model in ZEMAX under sequential mode, the stop surface is in the diffraction grating though I set it in the diaphragm plane.
![](https://uploads-us-west-2.insided.com/zemax-en/attachment/4e163ed8-e89c-4b30-9029-3616a21b163b.png)
How can I modify those settings.
Thank you.