Preliminary Assessment of Photonic Solutions Based on C-Band VCSELs for Multi-Tb/s Metro Networks

C-band InP vertical cavity surface emitting laser (VCSEL) exploitation can be appealing also for high-capacity transmission over hundreds of kilometres. Long-wavelength VCSELs can represent an alternative solution for the development of transmitters with reduced cost, power consumption and footprint by adopting direct modulation (DM) and single sideband (SSB) discrete multitone (DMT) modulation to achieve dense wavelength division multiplexing (WDM) granularity. Due to numerous hops between nodes inside metropolitan area networks the effect of filtering can severely impact the transmission performance. We present preliminary experimental assessments of DM VCSEL sources with multi-carrier modulation formats, for more than 50 Gb/s per-channel transmission to target a metro network including nodes, handling 25-GHz granularity.