FULL-MESH OPTICAL BACKPLANE WITH STANDARD MM FIBER RIBBONS

The rapid growth of ICT applications requires that data centers are now able to handle an ever increasing bandwidth capacity. Currently, the interconnections at data center level are managed through electrical backplane with copper connections. However electrical backplanes have now reached their limit in terms of transmission capacity and alternative optical solutions have recently been explored [1-3]. The main advantages offered by optical backplanes are: 1) no bandwidth limit; 2) reduction of backplane power dissipation [4]; 3) suppression of electromagnetic interference. Besides optical waveguides embedded in standard FR4 boards [1], which yet suffer from relatively high attenuation, optical fiber sheets have also been proposed as an easier solution to realize high-density and complex backplane [2]. However, this latter solution is not currently amenable to high-volume manufacturing processes. In this work an optical backplane prototype exploiting standard MM 12-fiber ribbons has proved a full-mesh optical connection between 8 boards, that is, each board provides bidirectional connections with each of the other boards.