Gain stabilization of EDFA cascade using clamped-gain SOA

Summary form only given. In wavelength-division multiplexed (WDM) optical networks, channel adding or dropping due to system reconfiguration or faults cause power transients and a residual power change on the surviving channels. Solutions based on the use of an idle channel at the transmitter level to make up for the variations of total optical power have been proposed to combat gain transients. In this paper, we introduce a new compact and reliable all-optical scheme based on a clamped-gain semiconductor amplifier to achieve gain stabilization in a cascade of erbium-doped fiber amplifiers (EDFAs).