1-Tb/s (100/spl times/12.4 gb/s) transmission of 12.5-GHz-spaced ultradense WDM channels over a standard single-mode fiber of 1200 km

We present a 1-Tb/s (100/spl times/12.4 Gb/s) transmission of 12.5-GHz-spaced ultradense (UD) wavelength-division-multiplexing (WDM) channels over a standard single-mode fiber of 1200 km. The UD-WDM channels are aligned within /spl plusmn/100-MHz errors using their beat frequency signals with a tunable laser source. The UD-WDM channels are modulated in nonreturn-to-zero format and amplified using erbium-doped fiber amplifiers to demonstrate the upgradability of existing WDM networks.