Optical amplifiers in dynamic networks with all-optical routing

Transparent amplified all-optical networks using conventional fibre amplifiers are vulnerable to transient interchannel cross-saturation when they undergo dynamic reconfigurations. Because the amplifiers saturate on a total-power basis, addition or removal of channels in a multi-access wavelength-routed network will tend to perturb channels at other wavelengths, which share all or part of the route. We present theoretical and experimental results of surviving channel power fluctuations in a cascade of five erbium-doped fibre amplifiers (EDFA) caused by channel addition/removal in networks employing all-optical routing and suggest measures leading to suppression of these power fluctuations. Application of all-optical gain-clamping, pump-power-loss-controlled EDFA and highly inverted amplifiers is discussed in detail.