KM3NeT/ARCA Optical Network

Laboratori Nazionali del Sud dellINFN owns and manages a deep sea infrastructure situated in Portopalo di Capo Passero where theARCA KM3NeT infrastructure is installed. The KM3NeT ARCA telescope is being installed at a depth of about 3500 m and the distance to the control station on shore is about 100 kilometers. The telescope will comprise more than 4000 optical modules in the detector arrays with a point-to-point optical connection to the control station onshore. In particular, the detector is optimized for the detection of cosmic neutrinos with energies above about 1 TeV. The expected maximum data rate is 200 Mbps per optical module. The implemented optical data transport system matches the layouts of the networks of electro-optical cables and junction boxes in the deep sea. For efficient use of the fibers in the system the technology of Dense Wavelength Division Multiplexing is applied. To comply with the scientific goals of KM3NeT , the implementation of the detectors has been subdivided into two phases in order to adapt to the time lines of funding sources and procurement procedures and to allow for adaptation or replacement of obsolete technical parts. The first implementation phase foresees the construction of 32 detection units for ARCA where synchronization is achieved by communication between a White Rabbit master onshore and a White Rabbit slave unit inside the optical modules. For the second phase of the project - adaptations are foreseen in order to have better scalability, reliability and standardization based on a full White Rabbit capable architecture (WWRS). The KM3NeT broadcast and WWRS optical data transport system will be presented.