Ultra-high-capacity optical packet switching networks with coherent polarization division multiplexing modulation formats and related technologies

Optical packet switching (OPS) subsystems have a crucial role in current optical access networks and may be essential in future access and datacenter networks, where the requirements for higher data-rates, transparency, reduced end-to-end latency and optimized energy consumption may be enabled by increasing the network granularity and introducing flexibility on both the line-rate and the modulation format at the optical layer. This paper reviews recent research on two important subsystems of such new generation OPS networks: a digital coherent burst-mode receiver (DCBMRX) for PDM-QPSK and PDM-16QAM modulation formats and a line-rate flexible coherent burst-mode receiver. Finally, we discuss a recent ultra-high capacity OPS experimental demonstration, with top switching speed of 12.8 Tb/s/port, that makes use of the aforementioned DCBMRX and electro-optical switching matrices based on (Pb,La)(Zr,La)O
3
(PLZT). The optical switching control plane is able to resolve packet contention by means of packet buffering and packet discarding.