The ratio of FSR to full-width half-maximum (FWHM) is the Finesse, which for the above case is 10.9. The quality factor (Q-factor) is a measure of sharpness of the resonance relative to its central frequency (ratio of resonance frequency to FWHM), which for the current setup is around 650.
OptSim Circuit allows modeling of PICs that are cascaded (or arranged as multi-stage). For example, the single-stage ring resonator PIC that we used in the discussion above can be cascaded as shown in Fig. 5.