Optical predistortion feedback linearization for suppressing the nonlinearity in optical amplifier

The investigation of a radio-over-fibre distribution system with optical pre-distortion feedback linearization of semiconductor optical amplifier (SOA) for communication systems has been proposed. The simulation verified OPDFB linearization for two tones CW indirect modulation to optical fibre. This technique has investigated linearization for the SOA amplifier by an OPDFB linearizer to cancel out the third order inter-modulation distortion (IMD) or four waves mixing. In this paper, we have used two channels and have seen more than 20 dB reductions in the spectral re-growth caused by the SMF and SOA. Amplifier non-linearity becomes more severe with two strong input channels leading to inter-channel distortion which can completely mask a third adjacent channel. The simulations detailed above were performed utilizing optimum settings for the variable gain and phase components in the error correction loop of the OPDFB system and hence represent the ideal situation of a perfect OPDFB system. The results suggest that OPDFB linearization allows successful transmission of multiple channels in a wireless-over-fiber system.