Morning Star: Are the optical interconnections of high speed circuits part of the “Lab-to-Fab” transition, where POET supplies the roadmap for integrating electrical and optical capabilities, but our customers are responsible for the "upon completion" parts?

No, optical interconnections are not part of the lab-to-fab transition. My impression is that the transition is agnostic of any specific application but focuses on the POET process as such. They will likely use a variety of PET/POET devices especially suited to support testing.

On the other hand, however, the PDK will allow "early stage exploration for “System on a Chip” (SoC) and optical interconnect architectures leveraging unique functionality and performance of novel POET/PET technologies" (CP page 19, highlighting by me).

To answer your question, I believe it will be up to chip designers aka POET customers to actually create chips for optical interconnects or for whatever. They will have the PDK at hand to play around with the POET toolset, put the pieces together, run simulations and find out how this stuff works. And I think they can order consulting and support by the specialists from POET Technologies.