Crosstalk estimation of 21.12 Tb/S Nyquist superchannels with hybrid modulation using trench-assisted multicore fibre
The transmission of 5 × 4.224 Tb/s Nyquist superchannels over 2688 km distance has been demonstrated using trench-assisted multicore fibre (TA-MCF) at different spans for the first time at reduced channel spacing. The channel spacing has been efficiently reduced from 32 GHz (before modulation) to 25 GHz (after modulation) using Nyquist superchannels with hybrid modulation to transmit 15 subcarriers in one superchannel without any distortion. Five Nyquist superchannels, each using 15 × 35.2 Gbaud PM-16QAM subcarriers (4.224 Tb/s), are transmitted over seven cores of TA-MCF with low crosstalk over the same distance. Further, by utilising the core-to-core rotation scheme, the inter-core crosstalk from the neighbouring cores has been reduced after WDM/SDM transmission.