Rainer: I find it interesting that they describe the micro-ring modulator as being extremely temperature sensitive, so they have to use heaters to compensate for temperature changes.

As I recall Ayer Labs zero change silicon 45nm (SOI) requires the micro-ring temperature to be maintained at 125’F (why 125’F? I expect it  is tuned to match the highest temp expected within the operating range of the silicon application). Again we look at the limitations to effectively optimize monolithic silicon for photonic functions. Definitely continue to throw a lot of money at it but think about what POET has done with very limited funds. Again functions are optimized separately in the best material set for that purpose. POET will no doubt use micro-rings for  higher order modulation schemes for advanced application in series  with MZI  but the package will be optimized to reflect temperature gradient.

POET will use the best that silicon offers and combine it with the extremely low loss dielectric stack waveguides. The silicon companies  can continue to put lipstick on a pig.

Got  to run…Emma has her ball and she is starting to pace.