I am designing Si3N4 double bus ring using VarFDTD. I simulated the design up to auto-shutoff threshold. I got some transmission ripples when I simulated the design up to 15000fs time. But when I increased the simulation time, the transmission spectrum was smooth but power dropped from 0dB to 5dB.
- May I know why power has dropped with simulation time? I am attaching the spectrum screenshot here.
- How can I solve this power dropped problem?
Please give me your valuable suggestion on this. Thanks.