Hope to have GeSn added to the library and allow user to input the concentration of Sn.
As you have noticed, our default material database does not include GeSn. I’ll make a note to ask our R&D team to consider adding this to the default database. However, it is also worth remembering that it is relatively straightforward for you to add new materials to the database.
Option 1: It is fairly simple to create a new Sampled Data material if you have the refractive index data in a tabular format.
Option 2: The Analytic material model might be useful if you have an equation that defines the refractive index. This material model might be particularly useful if the equation allows you to specify the fraction of Sn.
I also wanted to point out that the following reference provides some material data for GeSn. See figure 10.
E. Kasper, M. Kittler, M. Oehme, and T. Arguirov, “Germanium tin: silicon photonics toward the mid-infrared [Invited],” Photon. Res. 1, 69-76 (2013)