electric field propagation in a bent gradient index WG via FDTD
I'm trying to simulate light propagating in a bent gradient index WG in FDTD. I managed to import the geometry of the WG by importing straight sections of "Spatial (n,k) data" and rotating them. But i just cannot seem to get the light to propagate from one end of the WG to the other end. What usually happens ist that the highest intensity of the E-Field can be observed above the Material and in a straight line away from the source.
Im particularly interested in the propagation loss. Is it possible to simulate this via FDTD? And if so, how do I need to set up my sources so that the light propagates within the WG?
Any help would be much appreciated!