This paper reviews several key technologies to realize a transoceanic
wavelength-division-multiplexing (WDM) system with more than 100 Gb/s
capacity. The key technologies include a novel gain equalization schem
e, a broadband erbium-doped fiber amplifier, a chromatic dispersion co
mpensation technique at a transmitter, and a RZ modulation format. Emp
loying these new technologies, we successfully demonstrated a 32 chann
el 5.3 Gb/s (total capacity of 170 Gb/s) WDM signal transmission over
9879 km. (C) 1997 Academic Press.