You seem to be missing my point. POET's 850nm lasers developed by Dr Taylor used self  assembled quantium dot lasers at multiple  wavelengths. And as a side note the detectors were extremely sensitive.

The whole goal of  the Optical Interposer platform is to  provide exceptional  connectivity in a highly automated fabrication flow that allows for the best material sets to be combined seemlessly.

They are totally diferent animals.  Doing everything in a monolithic system is a comprimise. That is why your phone has so many different chips in it.