Learning Forum

[Guilin Sun]

The larger-than-1 result may indicate that the simulation time is not long enough. What is the persentage from log file at the end of simulation? 

To make the simulation stable, I personally do not use stabilized PML, as it can have large reflections. You should use standard PML with 64 layers. If this is not suffiicent, you can use the "custom PML", with the PML parametes the same as the Standard, and just increase the max PML layers and use it, say to 128 or more.

Since the device is long, the long simulation time is expected. You can simulate short staright waveguide/fiber with long taper part, use long enough simulation time say 10 times or more than you used right now, and let the autoshutoff min to terminate the simulation .

In addition, you can also use a time monitor at the far end and check its spectrum to see if there is srong resonance, which should not in such device.

You can also use more frequency points in the transmission monitor to have smoother result.