Guilin Sun
Ansys Employee

It is not known for me if the device is a simple straight waveguide with a nano paritcle on it, or a MMI component with the nanoparticle?

if it is the former, please significnatly reduce the simulation length, with only about one wavelength, move the source and monitor close to the nanoparticle, with long simulation time and smaller autoshutoff min.

also make sure the PML is about hald wavelength thick to effetively absorb the EM eergy. From the scrrensot it seems PML is thin.