Authored By Ethan Keeler
Currently, there is not a mechanism for OpticStudio to directly ingest surface roughness data directly. To model this effect, you need to use this data to create a bi-directional scattering distribution function (BSDF). Below is an image and equation showing the general form for this scattering model:
$$BSDF(\theta_i, \phi_i, \theta_s, \phi_s) = \frac{dL_s(\theta_s, \phi_s)}{dE_i(\theta_i, \phi_i)}$$
The BSDF can readily be used directly in OpticStudio. However, given surface roughness data, it is not trivial to determine its BSDF surface scattering model. Scattering is a complex phenomenon determined not only by the surface roughness and local topology, but also by the electromagnetic properties of the material. Depending on the needed accuracy, there do exist analytical or empirical calculations that can approximate scattering events for certain materials and specifications. These approximations can be found in the literature or reference books.
In the Ansys ecosystem, you could consider using Lumerical to model the near-field interaction with the measured surface roughness. From this simulation, you can export a BSDF model to be used in OpticStudio.
For more information on OpticStudio scattering models: What scattering models are available in OpticStudio? – Knowledgebase
For more information on Lumerical modeling of BSDF: Bidirectional scattering distribution function (BSDF) – Ansys Optics