Discussion Forum

Hello!

I want to simulate a photonic crystal mirror with the beam envelopes module (see attached project file). I chose the beam envelopes method instead of the frequency domain method because eventually I hope to simulate a very long waveguide.

I thought that pretty everything--the geometry, boundary conditions and port set up, should be the same as in the "dielectric slab waveguide example" (aside from some holes taken out of the waveguide), however, I keep getting an error that the solver doesn't converge when I try to do a parameteric frequency sweep (in particular a divide by zero error from the stationary solver). Am I making some obvious mistake? Or is it wrong to use the beam envelopes set up for this part of the simulation (I see that the photonic crystal example is also done with "Frequency Domain").

Also, I am not very clear on the different boundary condition choices (I have been trying to learn most of them from the examples). I believe that I understand the difference between a Scattering boundary condition and PML, but is setting up a "Matched Boundary condition" the same as adding a definition for PML? Also, why is the only boundary condition applied in the slab waveguide example "Perfect Electric Conductor?" I don't understand why this was chosen over a PML.

Thank you!