Experimental Study of the Intra-Channel Nonlinearity Influence on Single-Band 100G Coherent Optical OFDM Systems

We report on an experimental investigation of the intra-channel nonlinearity effects in single-band 100G coherent optical orthogonal frequency division multiplexing (CO)-OFDM systems. We first show that instead of using traditional single-polarization training symbols (TS's), which suffer from nonlinearity-induced nonuniform phase shifts, correlated dual-polarization TS's should be used in reduced-guard-interval CO-OFDM systems with short symbol durations. Next, we demonstrate that the intra-channel nonlinearity tolerance in CO-OFDM systems can be improved by employing fewer subcarriers for signal generation.