Kc. Lee et al., MULTIWAVELENGTH ALL-OPTICAL NETWORKS WITH WAVELENGTHS OUTSIDE THE ERBIUM-DOPED FIBER AMPLIFIER BANDWIDTH, Journal of lightwave technology, 13(5), 1995, pp. 791-801
Erbium-doped fiber amplifiers have become the dominating technology fo
r signal amplification in all-optical networks. One constraint of EDFA
's is that they have a much narrower bandwidth (approximate to 25 mm)
compared to the low-loss region (approximate to 200 nm) of optical fib
er. Instead of using only wavelengths within the bandwidth of EDFA's (
i.e. the inband channels) for communication, we propose to include wav
elengths outside the EDFA bandwidth (i.e. the outband channels) as wel
l in order to increase the number of wavelengths and/or channel spacin
gs that can be accommodated. Using outband wavelengths for sending mes
sages presents a new constraint, namely that only if the power loss fo
r transmitting a message is small enough can this message be transmitt
ed on the outband wavelength. We develop wavelength-routing algorithms
on arbitrary network topologies and wavelength assignments in hierarc
hical networks for sending messages subject to this constraint. We als
o analyze the SNR for inband/outband WDM signals.