Reply To: Difference between answers in version 2024 and 2017 lumerical mode solution

[Guilin Sun]

Which product you are using? FDE? Could you elaborate more how do you select the forward and backward direction in FDE?

If it is from 3D FDTD, you can change the source injection direction. But I tested this online case and the result is the same, since it uses bandstructure method regardless the source injection direction: https://optics.ansys.com/hc/en-us/articles/360042038613-Bandstructure-of-a-magneto-optical-waveguide