Here is the short PPT version,
This was presented at SEMIcon WEst 2013
https://mphotonics.mit.edu/docman/ctr/ctr-3/short-reach-interconnect-twg/719-ctriii-3semiconwest20130710hemenway/file
The latest slide, are VCSEL versus Si photonics solution.
I've seen such comparison somewhere else and oh yes there was in addition a third solution