Prototype pixel optohybrid for the CMS phase 1 upgraded pixel detector

The CMS Pixel detector phase 1 upgrade calls for an optical readout system operating digitally at or above 320 Mb/s. Since the re-use of the existing link components as installed is excluded, we have designed a new Pixel Optohybrid (POH) for use within this system. We report on the design and choice of components as well as their measured performance. In particular, we have studied the impact upon error-free link operation of the way the data are encoded before being transmitted over the link. We have thus demonstrated the feasibility of operating the new POH within the upgraded readout system.