Joint ATLAS-CMS working group on optical links. Lessons learned and to be learned from LHC

This note gives a summary of the lessons learned from the current generation of LHC optical links as installed for the ATLAS SCT and pixel detectors and the CMS tracker. A comparison of the costs for the different optical links systems is given. A discussion of the quality of the installed links and the methodology for long term monitoring of the links is given. A description of the technology choices and the reasons for these choices in the different systems is given. This historical summary is used to draw many important conclusions for the optical links to be used for SLHC.