On where the optical interposer is heading. When you view this link and you should keep in mind that POETs platform is not silicon photonics in the classical sense. All optical functions (and the electronics to drive the active optical elements) reside within the PIC because it provides the best material set properties. The electronics to drive modulation is on the silicon but extremely close to the pic and at a different node size because they are two different worlds. 

Anyway POET has a solution that will drive costs down as required to meet the objectives needed.

Definitely worth a listen because that is the world that I think POET and Team POET will over time disrupt. Pay close attention to thermal stability.https://www.youtube.com/watch?v=Y34o0lQ983c