A low-phase-noise dual-polarization 16-QAM CO-OFDM modulation system with a hybrid optical filter

Phase noise is a crucial impairment in coherent optical communication. In this paper, a dual-polarization 16 quadrature amplitude modulation coherent optical orthogonal frequency division multiplexing (DP 16-QAM CO-OFDM) modulation system with a hybrid optical filter has been proposed for phase noise reduction. This hybrid filter is a combination of an optical designed filter and an optical Gaussian filter. Linewidth of the input laser has been varied to generate phase noise. The simulation results have been obtained in terms of bit error rate (BER). It has been seen that the use of a hybrid optical filter mitigates the adverse effect of phase noise.