I work on PON and XGPON. Officially we work on a -25dB maximum, but I’ve seen circuits stable at around 30dB.
It’s surprising how many bad splices you can ignore before it gets problematic.
-18.5dB is going to limit you to either a really good fibre path, or a really short one. Unless you have options with long-range SFPs? The constant progress keeps my job interesting at least.
Kazumara@discuss.tchncs.de 2 weeks ago
I’m working on long range stuff so I’m not so familiar with PON specifically. Maybe I made some bad assumptions. Stable at -30 dBm receive sounds really impressive.
The one I was talking about is this, with 18.5 dB total budget, that is, min +4.5 dBm transmit, and min -14 dBm receive. This one is built with an APD.
In my kind of application, without splitter, this will get you about 30-40 km. We’ve got one of a slightly older type with 18 dB budget running between Fribourg and Bern for example.
I realize that PON stuff is quite different with the time slitting and I think wavelenght splitting too, at least in XGS-PON, but I was thinking the pure laser and diode physics would need to be the same.
For -25 dBm minimum the most similar of the ones we currently have would be this one which manages -26.9 dBm and is one of the ones with a SOA built in, or for the 10G stuff this one, which manages min -23 dBm but with only an APD and no SOA.
I’m thinking their 50G stuff must be closer to 100G than 10G transceiver design. So I wonder if they manage to make it without SOA.