Can I make my own GPON network with ONT and OLT sfp modules?

I have some GPON ONT sfp modules, and I know they behave like normal Ethernet SFP modules, as I'm using one in a switch to replace my ISP's router. I also have some optical fiber and I saw that GPON OLT sfp modules are sold on eBay and they are not expensive. What I don't understand is if I have to use those modules with dedicated hardware, or if I can just plug them in a switch like I did with the ONT module. Can anybody clarify?

I'd like to build my own little GPON network. I know it's not very useful in practice, but I just want to understand the technology.

Thanks!