Ring-Cascaded Sequential Micro-Ring Resonators Array as a Photonic Reservoir for Signal Equalization in Intra-Data Center Networks

A novel photonic reservoir using multi-ring resonators is described to perform signal equalization in a short-reach PAM-4 transmission system running at 112 GBaud. The proposed structure enables resonator-based optical feedback, which improves BER compared to DSP-based feed-forward equalization, while requiring only a single photodiode with no additional bandwidth, thereby reducing DSP complexity.