Power pre-emphasised OFDM for RSOA modulation in high speed WDM-PONs

Orthogonal frequency division multiplexing (OFDM) technique is useful for limited bandwidth reflective semiconductor optical amplifier (RSOA) modulation to design high-speed passive optical networks (PONs). However, the capacity improvement of using conventional OFDM format is severely degraded over the fiber transmission due to the presence of RSOA chirp induced RF power fading. Therefore, we proposed a pre-emphasis OFDM for RSOA modulation to enhance the system performance against both RSOA low bandwidth and high chirp parameter. Experimental results showed that the transmission speed is reached up to 17.1 Gb/s at the bit error rate (BER) within forward error correction (FEC) limit over 25 Km fiber span by using commercially available RSOA of bandwidth <; 1 GHz.