Hi Mohammed,
The depth of optical filter is the maximum value the filter can attenuate the signal. This means that if a signal with 0dB in some parts enter a filter with depth of 100 dB, the parts of the signal that are in the stopband of the filter would have a value of -100 dB in the output, and no less than that.
It is a parameter defined i OptiSystem and I think the default value of 100 dB is apt, as it is consistent with some other default values of other component. However, increasing it doesn’t really have any remarkable effect most of the time.
Regards
.
