Short-reach 200 Gb/s SDM Network Employing Direct-detection and Optical SSBI Mitigation

We propose a new transmission scheme for direct-detection (DD) short-reach networks based on transmitting the carriers and the data signals in separated cores of a multicore-fibre (MCF). With this scheme, a low complexity signal-signal beat interference (SSBI) mitigation approach is proposed at the receiver side, which may be required to compensate electronically the chromatic dispersion of the singlemode fibre. The performance of a 200 Gb/s binary NRZ signal in a MCF short-reach network employing the proposed transmission scheme is assessed by numerical simulation. The combined effect of the skew and the laser phase noise on the system performance is evaluated. It is shown that the SSBI mitigation technique enables distances up to 180 m when dispersion is not compensated, showing the potential to be implemented in intra data-centre (DC) networks, when the signal mean optical power is much higher than the carrier mean optical power, and when the SSBI estimation is not corrupted by electrical noise. The results also show that in systems with full dispersion compensation, a significant performance improvement is achieved by the proposed SSBI mitigation approach, enabling higher connection lengths.