direction coupler problem

I am using this software to solve a directional coupler problem
using EME Solver and I have following query:
I require to find the surface overlap integral of two waveguide couplers
in the core regions only. For this, I calculated s-parameters. But I found out that surface integral is
evaluated over the whole cross-sectional area (core as well as cladding)
of the structure contrary to my requirement of over core region only. And
I found no option of choosing the cross-sectional area corresponding to
core region for evaluating surface integral.


I am guessing this post may be a useful reference. It has some discussion about using a filter to “select” the region of interest for integration. If this is what you are asking for, similar idea should be applicable to the EME solver. I will suggest you to take a look at that and we can continue the discussion.