Hello, Jefflanum. Welcome to TechForum!
I’m not entirely sure I understand the requirement, here. Are you looking for transceiver modules that can convert from an electronic signal to the fiber and inform downstream areas of this electrical relay closing? Or are you looking for a relay that is itself a fiber optic part?
We have plenty of transceivers, here: https://www.digikey.com/short/zj0wd8. I would need more information to try and narrow down that list for you though, if it’s the right list to start with at all.