Feedforward Linearization Technique for Reducing Nonlinearity in Semiconductor Optical Amplifier

This paper investigates the first demonstration of linearization of semiconductor optical amplifier (SOA) using feedforward linearization. To improve the linearity and suppressing the four-wave mixing (FWM) of SOA, the amplifier uses the feedforward technique. This technique should be applicable to any microwave or even millimeter frequency band and any externally modulated laser. Link performance was evaluated for single-tone noise reduction and two-tone FWM suppression. Theoretical simulation results are presented, showing a distortion cancellation produce by SOA of better than 20 dB over 1550-nm single-mode optical-fiber cable. This technique has been used to successfully transmit data, both directly and indirectly modulated, using a laser diode at a 2.5-Gb/s light-wave transmission system in simulation.