I think POET is working to both improve silicon photonics with an integrated laser to showcase/demonstrate POETs OI capability which led to the Tier 1 paying POET to develope a full blown 400G OI based optical engine.

I believe that was a strategy put into place by both the Tier 1 customer who I believe to be Cisco and POET

Cisco's investment in Silicon Photonics can be improved by POET and that is probably what got their foot in the door.