Tb/s Transmission in Sustainable and Flexible Beyond-5G Metro Access Networks.

Tb/s transmission matching the requirements of future beyond 5-G mobile systems and high-throughput services in the future sustainable metro/access network is demonstrated. An innovative photonic transmitter module of a bandwidth/bitrate variable transceiver has been designed and developed integrating multiple directly modulated long-wavelength InP vertical cavity surface emitting lasers (VCSELs) in a silicon-photonics platform. Multicarrier direct modulation of each VCSEL combined with dense WDM multiplexing with a modular approach provides flexibility in the transported capacity to match dynamic bandwidth allocation, fine granularity, and scalability according to a pay-as-you-grow scheme. The use of VCSELs directly modulated with discrete multitone (DMT) signals is a sustainable technological solution in terms of cost, power consumption and footprint. Moreover, the adoption of multi core fibers (MCFs) allows to also use the space dimension for multiplexing, perfectly matching the proposed modular approach and coping with the mobile systems increasing throughput in an effective way. Here we experiment the propagation over 129 km, including 21 km of a 7-core MCF, with 57 Gb/s capacity per DMT -modulated VCSEL channel and 25 GHz WDM spacing, demonstrating more than 1.2 Tb/s total throughput thanks to the proposed modular solution.