Long-Haul Transmission of PS-QPSK at 100 Gb/s Using Digital Backpropagation

We experimentally investigate the generation and long-haul transmission of polarization-switched quadrature phase shift keying (PS-QPSK) at an uncoded datarate of 112 Gbit/s (37.4 GBd). In what is the first demonstration of nonlinearity compensation for PS-QPSK, digital backpropagation is applied in order to evaluate performance improvements. We find that, even at this high symbol rate, the maximum transmission distance of this format can be increased by 20% by employing digital backpropagation.