Mesh, Unidirectional
In this simulation, each wave will have an almost constant amplitude, so a very coarse mesh can be used in the propagation direction. Add a second mesh for this case, but first make sure that the newly added physics interface (ewbe2) does not contribute to the specification of the first mesh, Mesh, Unidirectional. If it does, it cannot have different parameters when specifying another mesh.
1
In the Model Builder window, under Component 1, click Mesh, Unidirectional.
2
In the Settings window for the Mesh, locate the Physics-Controlled Mesh section.
3
In the table, clear the Use checkbox for the Electromagnetic Waves, Beam Envelopes, Bidirectional interface.