We experimentally investigate multigranularity optical subband switching functionality between two superchannels with slight error vector magnitude penalty. One is 4×39 Gb/s polarization-division-multiplexed（PDM） quadrature phase shift keying discrete Fourier transform spread orthogonal frequency division multiplexing（DFT-spread-OFDM） superchannel with 12.5 GHz band spacing. The other is 8×29 Gb/s PDM-16-quadrature amplitude modulation Nyquist pulse shaping superchannel with 6.25 GHz band spacing. To the best of our knowledge, this is the first time that optical switching functionality for individual band between different superchannels with multigranularity is realized.
Fiber nonlinearity is one of the most important limiters of capacity in coherent optical communications. In this paper, we review two nonlinear compensation methods： digital backward propagation （BP） and nonlinear electrical equalizer （NLEE） based on the timedomain Volterra series. These compensation algorithms are implemented in a singlechannel 50 Gb/s coherent optical singlecarrier frequency division multiplexed （CO-SCFDM） system transmitting over 10 × 80 km of standard singlemode fiber （SSMF）.
Fan Zhang (State Key Laboratory of Advanced Optical Communication Systems & Networks, Peking University, Beijing 100871, P.R.China)
