Ansys Employee
nA very fine mesh is often required at metal/dielectric interfaces where the field amplitudes rapidly change over a short distance, so it's expected that the results won't converge until the mesh is on the order of nanometers. Have you tried reducing the mesh even further than 1 nm to see if the loss converges? It might help your testing to use metal BCs, so the only loss in the system is due to absorption in the Au and not radiation losses through the GaAs layer into the PML boundaries. You can also speed up your testing by using symmetry boundary conditions on the x min boundary, either anti-symmetric or symmetric, depending on the polarization of the mode you are interested in. Please try that and let me know if it helps.