MULTIWAVELENGTH ALL-OPTICAL NETWORKS WITH WAVELENGTHS OUTSIDE THE ERBIUM-DOPED FIBER AMPLIFIER BANDWIDTH

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.