Reply To: How to select the simulation time to accurately calculate the Q factor.

[Guilin Sun]

May I know how do you get the Q factor vs time?

When Q factor is over a million, simulation time might need to be long, and choose only the highest Qs and use log scale to plot the intensity vs time and see if it is straight line. Please refer to this link https://optics.ansys.com/hc/en-us/articles/360041611774-Quality-factor-calculations-for-a-resonant-cavity and check the 2D example.

You may use its analysis group (high Q) for your simulation file, and place it near where it gives the highest Q.

I personally do not use too many time monitors, since the signals are summed up, and the low Q monitor signal may affect the high Q signal. You can use more such analysis group, and each uses a few time monitors. You can easily move the groups to where you consider the signal is strong for the highest Qs.

This might need a few iterations to get the final result.