I know that couple of networks cards exist - PCI cards for PC - that allows direct fiber optics connectivity, but my question remains trying to replace a traditional media converter (Fiber Optics to RJ45). And also trying to do it in the lowest space possible.

Also if somebody knows how to do it in a Raspberry PI. It would be super useful as well.

 

Yes, but the solution might not be ready made for your application. High end audio devices often use an RS-485 differential transceiver to do optical interfaces like TOSLINK and others.

 

"Yes, we can".