Guilin Sun
Ansys Employee

The frequency-domain monitor records data for any specified wavelength. The data is a mixture of all modes that were excited during the propagation. So the monitor is not a good way to get the single mode data.

To get data for a specific mode, you can directly use a mode source to do the simulation, without importing and exporting. You can also set the mode source to be broadband.

I am not sure your purpose. If you just want to know the mode profile, you can also use a mode expansion monitor on the waveguide to get the mode properties.