Ok thanks Aadil for reply
Plz let me know the sample rate is dependent on data rate.We cannot alone decrease or increase sample rate rather with data rate.so when data rate is higher,then sample rate is higher.Consequently,noise power is higher when PSD is checked inside box.
I am not getting what you recommended…..again asking in real systems/simulations on optisystems whether we should check or uncheck the PSD option???( plz note that i have to add white light in my simulation)