Learning Forum

[Amrita Pati]

Hi Guodong, 

I spoke to the R&D team on this. Unfortunately, they also agreed that the large index contrast can make it very challenging for RCWA to attain convergence. The last thing that they recommend is changing the number of mesh cells. I believe the "mesh type" of your simulation is "auto", which automatically refines the mesh based on the number of k-vectors. You can change the mesh type to "custom":

Then fix the k-vector at one value (let's say 1000), and increase the mesh cells, for example: 100x100, then 200x200, and so on. Let me know if you see any improvements.

Regards,
Amrita