56 GBaud PAM-4 100 Km Transmission System With Photonic Processing Schemes

Analog photonic computing has been proposed and tested in recent years as an alternative approach for data recovery fiber transmission systems. Photonic reservoir computing, performing nonlinear transformations of the transmitted signals exhibiting internal fading memory, found advantageous this kind processing. In work, we show that effectiveness memory depends significantly on properties signal to be processed. Specifically, demonstrate two experimental post-processing schemes a 56 GBaud PAM-4 system, with 100 km uncompensated standard single-mode direct detection. We that, systems significant chromatic dispersion, contribution reservoir's computational performance is limited. comparison between performances extreme learning machine fiber-based configuration, find both offer equivalent recovery. The eliminates necessity external recurrent connectivity, which simplifies system increases computation speed. Above 31 dB OSNR, photonics-based equalization exhibits lower BER than respective offline DSP-based KK receiver.