Reduction of cross-gain modulation in the semiconductor optical amplifier by using wavelength modulated signal

A novel dual-input Mach-Zehnder modulator was used in conjunction with a wavelength modulation scheme to remove the cross-gain modulation in the semiconductor optical amplifier (SOA). Eight 10 Gb/s wavelength-division-multiplexed channels are transmitted over 75 km of dispersion-shifted fiber with a semiconductor optical amplifier as an in-line amplifier, with less than 1.5-dB penalty.