Probabilistic Shaping Ofdm Optical Signal for Wavelength Conversion

In this paper, we have experimentally demonstrated the transmission of probabilistic shaping (PS)-64 quadrature amplitude modulation (QAM) orthogonal frequency division multiplexing (OFDM) signal after all-optical wavelength conversion (AOWC) in homodyne coherent detection system. In additon, AOWC based on four-wave mixing (FWM) can be carried out through the highly nonlinear optical fiber (HNLF) by adopting co-polarized dual-pump scheme. To the best of our knowledge, it is so far reported that PS-64QAM OFDM signal can be transmitted in the homodyne coherent detection system after AOWC based on FWM by adopting co-polarized dual-pump scheme. Moreover, we have theoretically analyzed the chosen co-polarized dual-pump scheme and exhibited that wavelength conversion does not change the probability distribution of PS signal, as well as the order of OFDM subcarriers can be maintained unchanged. We experimentally demonstrated that the OSNR penalty of the 64QAM signal with PS is about 0.5 dB compared with 1dB without PS at BER of 1×10 -2 when baud rate is 20Gbaud