All-optical two-channel 2R regenerator for time-interleaved PAM signals

All-optical multi-channel regeneration of advanced modulation signals is necessary for high-speed larger-capacity optical communication networks in the future from the cost point of view. As for the Mach-Zehnder-interferometer (MZI)-based pulse-amplitude-modulation (PAM) regenerator, we put forward the delay-complementary transmission scheme to avoid the crosstalk of cross-phase modulation (XPM) between two channels. The proposed scheme can ensure the optical power transfer performance required for multi-channel regeneration of time-interleaved PAM signals, regardless of differential group delay of available high nonlinear fibers. All-optical two-channel 2R regenerator for dual-wavelength RZ PAM-4 signals is established by simulation and the noise reduction ratios are up to 9.05 dB and 9.17 dB, respectively.