Coatings are an important part of an optical system. Coatings can impact light transmission, polarization, phase, etc. Therefore, OpticStudio fully supports coatings in both Sequential and Non-Sequential Modes. 

For Sequential Mode, you can apply a coating to any surface by opening its properties and viewing the Coating setting. 

For Non-Sequential Mode, you can view the Coat/Scatter settings on the object properties tab. 

Coatings are defined in the OpticStudio Coating Catalog. In the catalog, there are many pre-provided coatings from Zemax as well as coating manufacturers. You can also define your own coatings. The syntax for custom coating definitions is described in the Help File:  The Libraries Tab > Coatings Group > Defining Coatings. When using custom coatings, we recommend not adding them to the default coating file COATING.DAT provided by OpticStudio. Rather, user should make a copy of the coating file and rename it using a different file name. This is because the default COATING.DAT file gets overwritten every time OpticStudio updates. Renaming your own coating file helps prevent loss of custom coatings. 

Once the coating is applied to the surface, OpticStudio offers a tool to analyze coating transmission and reflection on a given surface. You can find this tool under the Analyze tab\Coatings dropdown menu. Coating transmission and reflection are plotted against angle of incidence as well as wavelengths. This tool helps you understand coating effect surface by surface. Especially for customized coatings, we recommend using this tool to check transmission/reflection to make sure coating is properly implemented in the coating file.  

You can find more detailed information on using coatings here in the Help File: The Libraries Tab > Coatings Group > About Coatings > Specifying Coatings on Surfaces.