[windy herlinParticipant]

hi all
I want to know about the loss comes from Bessel Bandpass Optical Filter which filter the specified lamda and rejact the others.
I already test it when the input power to the Filter is about -20 dbm, the output is abut -26.02 dBm. whre does the loss come from?
with regrads

[windy herlinParticipant]

Hy all
I already make the TWDM PON simulation for my final project
pardon me, but can you help me to check if this network is wrong or not
hope to receive your comment