this kind of optic fiber is probably only plastic so for a full DIY , you can use also fishing wire with a big power led or an old chistmass tree optic fiber lighted.....
Do you have interest to try OH2 together with MySensors Ethernet Gateway to get working?
I do not have enough force to push developers to make this happen. At the moment there is some problem on this, because full control is not possible. I think that MySensors Serial Gateway is working with OH2, but I don't like to use it. I like to connect my devices into LAN not cabling via old fashioned way using serial wires.