Hello Liu,
1. The “Resolution Bandwidth” setting in the RF Spectrum Analyzer (or optical spectrum analyzer) acts similarly to the actual instrument. It behaves like a filter to clean the received signal by filtering high noise out of it.
On the other hand, to increase the number of samples in the signal, you need to go to the main project layout, where you need to increase the number of samples per bit.
You need to be careful with the resolution bandwidth setting to avoid creating distortion to your signal.
2. Please refer to the description of signal types and structure in OptiSystem documentation.
Typically, you need noise pins in the setting to view ASE noise of EDFA. Parametric signals will not show ASE. It represent the signal as a single valued sample.
Regards,
Ahmad