Reply To: How to calculate the effective index of the gap in an Au film in MODE?

[Amrita Pati]

Hi,

Thanks for sharing the screenshot! It can be hard to find modes in these metallic structures sometimes due to a large number of spurious modes like the PML modes (most of the energy resides in the PML). These modes are automatically removed from the Mode List as they are not physical modes. But when the solver calculates the modes, it still counts them. So, if the solver only finds spurious "number of trial modes", then it will stop looking for physical modes. So, there are two things you can do. The first thing is you may increase the number of trial modes, so that the solver looks for more mode solutions to the eigenmode equations. Secondly, if you have a rough estimate of what the effective index of the mode would be, then you can use this value in the search near n field in the Eigensolver Analysis Window. 

Regards,
Amrita