Reply To: RCWA results are quite different from FDTD

[Amrita Pati]

Hi Guodong,

I looked into it a little bit internally. It seems that we have seen convergence issues in RCWA while simulating metallic structures, when there is a large refractive index contrast. This has also been documented: https://web.stanford.edu/group/fan/publication/Liu_ComputerPhysicsCommunications_183_2233_2012.pdf.

It is common to use a large number of k-vectors in plamsonic structures (like you are using) to gain convergence. And as I previously mentioned, using the tangent vector field method will help. Let me know if you are able to see improved results.

Regards,
Amrita