From the  Nov 2018 tech update

SV:

A word on Silicon Photonics which is another competing integration platform for photonics integration. The Optical Interposer platform not only provides a versatile chip-scale assembly platform for photonics in general, but it is also compatible with more conventional silicon photonics solution. This has opened up a new opportunity for silicon photonics-compatible component-integrated waveguide solutions in addition to fully integrated optical engine solutions. Our waveguide integrated active indium phosphide devices that has detectors or lasers which are a critical component of the Optical Interposer platform are also directly compatible with conventional silicon photonics technology. The vast majority of today's silicon photonic solutions do not integrate lasers at wafer scale. Relegated to a die scale assembly, the true merits and cost advantages of wafer scale integration are lost. POET’s waveguide integrated active indium phosphide components that are developed as part of its Optical Interposer platform solutions provide a light source that can be integrated into silicon photonics devices, enabling cost advantages of wafer scale integration