Hi Joe,

Those coatings are defined in your Coating File. For each OpticStudio file (*.ZMX/*.ZOS), you have a Coating File associated. You can select different Coating Files by going in the Setup..System Explorer..Files..CoatingFile drop-down menu. You can also view the current Coating File by clicking Libraries..Coating Catalog. But, I personnaly prefer to browse it by using Libraries..Coatings Tools..Edit Coating File. I’ll explain why in a second. When you choose the latter route, you are prompted with a message asking whether you wish to first save your current Coating File elsewhere to prevent making permanent changes to it. If you don’t intend to modify the Coating File just click No. The reason I like to browse the Coating File that way is because you now have a magnifier icon at the end of the ribbon in the top-left corner of the window containing your Coating File. This magnifier allows you to search for a particular coating inside the file, and I believe this is not possible if you just open the Coating Catalog somehow (I could be wrong). This is what it gives for SPLIT:

I let you browse the Help File to read about IDEAL coatings, but the green comment in the screenshot gives you an explanation. Basically, SPLIT means half the intensity is transmitted, the other half is reflected, and nothing is absorbed.

I hope this helps and take care,

David​​​​​