The POET technology or POET platform contains both the optical ("O") and the electronical ("E") side of the technology, while PET contains the electronical ("E") side only.

I once posted the following chart explaining their relationship:

That is, POET is a true superset of PET, or in other words, if you have POET you also have PET, because POET includes PET. And we know we have both, because the detector (optics) in the VCSEL transceiver is working and the transistors (electronics) are also working.

So since we have POET, we also have PET, and there's simply no point in building an extra theory around PET.