Richter, T.T.RichterSchmidt-Langhorst, C.C.Schmidt-LanghorstElschner, R.R.ElschnerKato, T.T.KatoWatanabe, S.S.WatanabeSchubert, C.C.Schubert2022-03-122022-03-122014https://publica.fraunhofer.de/handle/publica/38534710.1364/OFC.2014.Th1D.3We generate an ultra-dense 400-Gb/s superchannel by combining four spatially distributed 28-GBd-Nyquist-16QAM-sub-carrier transmitters using optical processing in nonlinear fibers. The multiplexed sub-carriers are precisely frequency-allocated with guard bands down to 0% and achieve bit-error ratios below 3.8×10-3.enconference paper