I am trying to simulate the reflection from a photonic crystal at normal incidence (incident medium is air, as seen in the file). I set up a plane wave source and a monitor behind the source. The results from the Reflection exceed 1 at several frequencies. Changing the size of mesh step size didn’t affect this result; I also tried increasing the number of layers in the PML, and that also did not appear to have an effect. I think the y boundaries are far enough from the source that there shouldn’t be spurious interactions there. I’ve attached the file. If you could tell me why I am measuring a reflection over 1 and how I can fix it, I would appreciate it.
PC_reflection.fsp (303.1 KB)
Graph of reflectance.