In a new record, National Institute of Information and Communications Technology (NICT) has demonstrated switching capacity for short-reach data-center networks at 53.3 Tb/s.
The world-record setting demonstration was delivered by NICT President Hideyuki Tokuda. The demonstration made use of spatial division multiplexing (SDM) over multi-core optical fibers (MCFs) as well as a newly developed high-speed spatial optical switch system that enables full packet-granularity.
One of the major motivations behind the need for new switching capacity is the nearing of physical limits of optical networks using standard single mode fiber (SMF) owing to continuous increase of network traffic demand. Researchers have long been proposing SDM technology, including MCFs, to alleviate the capacity limits imposed by SMFs. Further, it is also important to reduce the granularity of optical networks.
If we look at current scenario, commercial optical networks can switch optical wavelength channels that operate continuously in time; however, the actual information is still being transmitted over the network in packets. Hence, the capability to transmit these packets directly on the optical domain can increase the overall network efficiency and replacing electronic switching with optical switching can also reduce the total end-to-end energy consumption per bit.
As far as the current technology demonstration goes, NICT developed a high-speed 7-core-joint optical switching system capable of switching all the cores of a 7-core MCF simultaneously with an ultrafast switching speed of 80 ns. The system consists of multiple electro-absorption (EA) optical switch elements with several nanoseconds switching speed; switch controller, capable of reading the destination address of packets and controlling multiple EA switches simultaneously.
The optical switching system can be used in an optical network switching node to realize several functions. Using this optical switching system, NICT built a testbed of a time-slotted optical network, capable of achieving full packet granularity. This testbed used 64 wavelength channels, modulated at 32 Giga Baud with polarization division multiplexing (PDM) quadrature phase shift keying (QPSK).
The system delivers a nominal capacity of 53.3 tera bits per second. In the testbed, three MCF segments were used: a 19-core 28 km fiber, a 19-core 10 km fiber, and a 7-core 2 km fiber. On each fiber, 7-cores were used in this demonstration to carry information signals.