Reply To: How to obtain the propagation loss in phase-shifted bragg grating waveguide

[Guilin Sun]

You can use FDTD simulation to get Q and resonate frequency. Pleae refer to Quality factor calculations for a resonant cavity

other examples  https://optics.ansys.com/hc/en-us/sections/360006919094-Resonators

You can use both FDTD and EME to get the totla loss, with loss=1-R-T.

However, if the loss is small, the result might be very senstive to mesh accuracy and other factors.

Please check which method is better for you.