Oldgreg: However the focus back then, was to produce a 40nm PET chip as a single entity, for customers that don't require the Optical element of POET. … Management just decided to plough on with the full intigration, since partners of PET fell by the wayside.

Yes, the new management decided to go fully into photonics, because they saw where the growth rates would be over the coming years. And if you want to position your company as a global player in photonics, there's simply no place for PET-only solutions, because they would only distract management's attention away from what they are focusing on.

On the other hand, electronics monolithically integrated with optics, i.e. POET ⊃ PET, makes a lot of sense since it is the differentiating factor over the competition.