“…Ten channels were transmitted over 400 km with a spectral efficiency (SE) of 0.7 b/s/Hz (143 GHz channel spacing). Currently, the availability of mature high-speed electronics and optoelectronics is limited and thus most binary 100 Gb/s demonstrations have occurred in research labs [8,32,36,37,39,50]. In an effort to improve the spectral efficiency and reach, more advanced modulation formats are being explored [12,47].…”