highlydoped
phosphate-glass fibre. Such a device exhibits excellent properties
of stable clamping and requires only 4% of extra pump power for
gain stabilisation. We have also removed the spectral-hole-burning
effect by interleaving lasing and channel wavelengths. All-fibre
compact erbium-ytterbium-doped amplifiers seem a very promising
and mature technological solution for high-capacity reconfigurable
WDM networks and will outperform fibre amplifiers with standard
doping levels.