Highly scalable optoelectronic packet-switching fabric based on wavelength-division and space-division optical switch architecture for use in the photonic core node [Invited]

We propose a highly scalable optoelectronic switching fabric with a wavelength-division and space-division optical switch architecture and a skew-insensitive frame-by-frame synchronization scheme. The optical switch architecture offers superior scalability, modularity, and transmission quality compared with a conventional space-division optical switch. It can accommodate more than terabit/s capacity and reduce the number of semiconductor optical amplifier gates by a factor of 8 for a 256 × 256 switching fabric. The proposed synchronization scheme automatically compensates for the transmission skews among the packet interfaces and the switching fabric, and with this scheme it is no longer necessary to adjust cable length and transmission delay in erbium-doped fiber amplifiers (EDFAs) and interconnects across shelves and cabinets. We prove the feasibility of the switching fabric by implementing an actual asynchronous transfer mode (ATM) switching node and demonstrate its operational stability, which we call the photonic core node (PCN). The PCN will accommodate not only ATM switching but also wavelength-division multiplexing (WDM) optical path grooming and multiplexing as well as Internet Protocol (IP) routing by supplying it with IP packet buffer interfaces, because optical switches are bit-rate and format independent. We believe that this technology will be the key to the installation of future broadband networks.