One of the problems when attempting to provide a wide area view  of what POET does and why is is unique  is that there is a lot to this story. How this platform manages thermal gradient at the chip level which is just so important for both passive and active photonics to work efficiently. It really blows everything out of the water in terms of the layout that can be arranged to isolate thermal signatures and the fact that POET waveguides are more tolerant to temperature variation because of the athermal characteristics of the secret sauce (the dielectric stack). Its ability to shape and control the light at transitions and make it fit into and out of single mode fiber that is 1/10 the diameter of a human hair. 

As I have said before. There is a lot to work with here.